EDIT: As HearthPwn leaked the whole card list to you, I'll now give you examples from the rest of the cards as well. I can confirm the HearthPwn cards are not fake, they are absolutely legit. On top of that, their card information is more recent than the info I had.
I. CARD LEAKS
1. Unknown cards that I leaked for the first time:
Grounding Totem - 1/0/3/ Redirects the next direct damage spell to itself (This card existed in an earlier version of the game, but as the Shaman already has 25 cards, this one was either scrapped for being too problematic, or is planned for a later release)
7/5/8 neutral minion. Legendary quality. Increases attack on minions. Art is the same as the Vanndar Stormpike from WoW TCG (this card is also from an earlier version of the game, but is either scrapped or will be released later)
(1) Arcane Blast - Deal 1 damage. Draw a card. Rare quality. Art is same as in the WoW TCG. (I'd be glad if it could be somehow confirmed that such a card existed at some point, because it no longer exists in the game. And I mean there isn't a chance this card is postponed and will be added in a later patch. What happened to it is that instead of a Mage card, it was reworked as the Rogue card "Shiv" instead)
2. Unknown cards that I leaked for the first time and are now confirmed:
Sorcerer's Apprentice [2/2/2] - Your spells cost (1) less. (Mage minion)
(1) Mirror Image - Summon two 0/1 minions with taunt
(7) Flamestrike - Deal 4 damage to all enemies enemy minions. Epic Common quality. Art is same as in the WoW TCG. (In a previous version of the card it was Epic quality and dealt 4 damage to the enemy hero too, but was probably nerfed for being way too powerful like that.)
(2) Frost Nova - Freeze all enemy minions. Basic quality. Art is same as in the WoW TCG.
(3) Spellstealbender - Secret card. Rare Epic quality. Art is different from the WoW TCG.
Whiteout (The card was pretty much taken from the WoW TCG, bearing the same picture, a similar effect and the same name, but now you know the card by its new changed name - Blizzard)
-Third Shaman Hero Power Totem - 0/2 totem, gives +1 Spell Power.
Flametongue Totem - 2/0/3 totem, gives a friendly adjacent minion +2 Attack. Basic quality. Art is the same as the Blazing Elemental Totem
(3) Hex - Transform a minion into a 0/1 Frog with Taunt.
Lava Burst (3) Rare quality. Art is the same as the Magma Spike WoW TCG Card
Rockbiter Weapon - same art as in the WoW TCG. (Art has been changed.) Basic quality.
Earth Elemental - 5/7/8 Taunt, Overload (3). Epic quality. (I don't see this card in the HearthPwn database, but this should be the third Epic-quality Shaman card.) Update: Now "revealed" in a Tuesday Update
Light's Justice - weapon, 1/1/4, same art as the WoW TCG card
(2) Holy Light - Restore 6 Health. Basic quality. Art is the same as Father Gustav WoW TCG card
Hunter's Focus - same art as the WoW TCG, 4 mana cost, increases attack power (was reworked into Multi-Shot with a new effect)
Fen Creeper [5/43/6/taunt] common quality
4/2/4 minion. Basic quality (The card I meant was Dragonling Mechanic)
4/2/4 minion, same art as the "Tinker Bixy Blue" WoW TCG card. Basic quality
Ironfur Grizzly - taunt. Basic quality
3. Missing information on known cards that I leaked for the first time and is now confirmed:
Ogre Magi 4/4/4 Spell Power +1
Reckless Rocketeer - 6/5/2/Charge
Grom Hellscream - art is the same as the cover of "Rise of the Horde" novel
Arcane Shot - art is the same as the Chimera Shot WoW TCG Card
Explosive Shot - same art as the WoW TCG card
Snipe - art is the same as the Delinar Silvershot WoW TCG Card
Scavenging Hyena - same art as WoW TCG card "Banzai"
Houndmaster - same art as the WoW TCG card "Leader of the Pack"
Timber Wolf - same art as WoW TCG card "Fang"
Kung Mukla - Art is the same as in the WoW TCG
Flare - same art as the WoW TCG card
Gladiator's Longbow - same art as the WoW TCG card "Merciless Gladiator's Crossbow of the Phoenix"
II. POST-RELEASE INFORMATION (~Expansions & Major patches)
1. I think World of Warcraft won't get a Demon Hunter class soon - if there were such plans for an upcoming Burning Legion focused expansion, Metzen wouldn't let Illidan be a normal card and would save him as a Hero. Well, that if some cards aren't also included as heroes at some point.
2.The team is currently making discussions about which Warcraft characters to be saved for future Heroes (class representatives) - for example Velen is currently a normal card instead of a hero, and Anduin is the Priest Hero. The most likely plan for now, is making at some point possible that some characters could be used in both card versions and as a Hero. This means upcoming legendary Thrall minion for shamans, legendary Anduin for priest, Garrosh minion, Jaina minion, etc. At the same time, making Edwin VanCleef hero, Velen hero, Grom Hellscream hero, etc. The hero and minion versions will likely be two different things though, not both-in-one as Jaraxxus.
3. Update on the above:
The team decided to put them lower in the priority list. The decision was made because of the complexity that comes from such a feature. Do you make all Warcraft characters exclusive to either a hero or minion? If there is Antonidas minion and mage hero, would they be 2-in-1? If this is the case, wouldn't such minion cards become too popular because of the given benefits that obtaining them would unlock you an additional hero? If they are separate beings, how could a Thrall hero summon the Thrall minion? Should they be mutually exclusive, meaning you can't have their effects as part of the same strategy? If there is such a restriction and you use a different Shaman hero, then how could you summon the Thrall minion if your opponent himself is using the Thrall hero??? Is there less confusion if the Thrall minion is the pre-Cataclysm version of him? How much realism do you compromise for the gameplay?
As you see, a lot of questions. They can be decided upon, but the devs need to first see what the community really wants as a priority once the game is released. Especially in the current rapid development progress, the team doesn't have the time to sit down to discuss all of this now. In the end, maybe the best choice would be to implement all the heroes as $5 "skins" that just change the picture and voice, without different hero powers. It is simple enough for a casual title, and selling visuals in F2P games is known to be profitable. And there are a lot of picky people that don't want their class hero to be alliance / horde / male / female / blood elf / human / Garrosh.
4. There is an obvious reason there isn't currently a Lich King card........ The team is 100% making LK/Arthas the future DK Hero. One could say he is much more powerful than all the other Heroes to be placed alongside them, but Chris is determined to use him to hype the future DK class. Also if LK was just another powerful legendary card, the team would not be able to make a Frostmourne weapon card for him. And popular stuff like this sells the game too much to stay as a missed opportunity. They also better make that legendary Ashbringer at some point - for a Tirion hero, just as there is currently a Doomhammer for Thrall. (Update: Oh, thanks for giving Tirion his Ashbringer just as I said... )
5. The team has plans for "new" attributes - they are not completely new, it's minions that can include one of the statuses you can currently give to a minion. For example this card, useful for Warrior decks: Wounded Defender - 3/4/2 Damaged. (Update: Injured Blademaster and Imp Master are very similar to what I gave you as example, and somewhat serve as testing cards for this. Of course, a specific Damaged attribute is not needed if the card's effect just includes dealing damage to itself, but later this could change. For the start of such a game, a lot of effects start as a gimmick of a specific card, but can be added later as a baseline attribute, included in many new cards. Also, if such effects become baseline, they take much less card text space, allowing for another effect to be included in addition to this one.)
6. While talking about Deathwing, I mentioned there are no plans for other minions with such high stats, except if something like Ritual summon is implemented. A mechanic called Ritual / Sacrifice / whatever works the way I described: The minion has these high stats, but can't be played unless you destroy friendly minions for a total of X attack or more, X health or more, also maybe a combination of the two. Now I'm adding onto this - Void Terror is actually the testing card for this mechanic, and adding a new major effect in the game similar to his special one is considered and will be decided based on the use of Void Terror.
III. PRE-RELEASE INFORMATION (~Beta)
1. The number of cards is not 300, they are currently more than 350.
Update: At this time, the current number of polished collectible cards is 385-400 (there are a lot more cards, including DK ones, but this number includes only the really polished, as in perfectly balanced and ready for release even now).
2. Nozdormu's effect is a good example of something that looks pretty straightforward at first glance, but in reality is more complicated. The idea of the effect is to give the players little time to think. But if you activate cards as shown in the presented gameplay video materials, the card's effect could become a disastrous frustration. What danger could there be in a 15 second timer? Animations. If you have to wait for an animation to end before other interactions, turns could end before you even finish attacking with your current minions, because some effect animations are over 5 seconds. Good luck summoning Jaraxxus - he alone would eat half your time along with the warlock. The obvious solution is making the timer active only outside animations, but it doesn't fix the problem - with so much animations in a turn, and a lot of them being slow, you'd have more time to think during animations (15+ sec) than outside them (15 sec) and it ruins the card's idea. To prevent this, you have to count animations in the 15 seconds, but be able to "chain" your actions during them - this is currently how interactions are handled in the game.
(Update: Someone in the comments mentioned speeding up animations - this is also an option, but something like this would never be implemented in Hearthstone. Speeding the animations 5 times looks unrealistic and breaks the atmosphere / ideology of the game. Other games may use speeding up turns, but HS would lose its flavor from something like this.)
3. To address the confusion about using cards for another class (by Thoughtsteal/Mind Vision/Lorewalker Cho or other) - the way the game is designed, the restrictions on spells of a different class are that you simply don't have have the option to manually put them in your deck. You can still use them if you get one in a duel with cards that do so.
4. The "Finding Opponent" has a very small chance to actually land on the hilarious options. (Update: I really hope this will stay in the game and is not just an internal joke that would be removed from the public versions of Hearthstone.)
5. Here's an interesting situation that is actually possible in a match. Consider these perfect card draws:
Enemy starts first with 1 mana. (You are second)
Your 1st turn, you have 1 mana and 5 cards in hand. Innervate - now you have 3 mana. Innervate - 5 mana. Nourish - down to 2 mana. Wild Growth - 0 mana. End turn.
Enemy turn, he has 2 mana now. probably deals 2-3 damage to you this turn.... nothing scary.
Your 2nd turn, you gain 1 mana by rule and have 2 from the nourish and 1 from the WG. 1+1+2+1=5 mana. You draw a card and now have two in your hand. Activate them - Nourish - 2 mana now, Wild Growth - 0 mana. End turn.
Enemy turn, now he has 3 mana. Probably deals another 3-4 direct damage to you.... as if anybody cares.
Your 3rd turn, you gain 1 mana naturally, 2 from Nourish, 1 from WG, 1 from The Coin - 5+1+2+1+1=10 mana! You draw a card..... HELLO THERE, DEATHWING! :cool:
Other big minions work too, like Illidan, Alexstrasza, Nozdormu, Onyxia. Even if the enemy does something to your minion on his next turn (he will have 4 mana), you already have 10 mana every turn....
Being serious now, of course these exact card draws would rarely happen (even though you have control of your first hand). This was just to show the most extreme version of sacrificing all hand, board and hero life to reach 10 mana on your third turn for the card you are about to draw. The same strategy (but less extreme) is still very good in normal games, just mulligan your first hand to get as most WG's, Innervates and Nourishes as you can. Throw some cheap taunt minions like Shieldbearer, or you can just use a Healing Touch to negate that early damage. Most importantly, make sure to have those late minions for mid game that will win you the duel. As far as lategame goes, while Priest is probably the safest lategame hero, the team's goal is making Druid the fastest lategame-reaching hero.
(Update: Even though the above what-if scenario is still a cool little thing, it's outdated by even more ridiculous hypothetical situations that use the new effect of Millhouse Manastorm)
IV. PRE-ANNOUNCEMENT INFORMATION (~Alpha)
1. Charge effects were used on more cards in the beginning, but were proven too powerful with certain stat distributions - a [3/3/1 charge] minion currently exists that is really a bigger annoyance than a 3 spell for 3 damage, because that minion stays alive and requires the enemy to react to it, instead of just doing whatever he wants - it is always best if you can force the enemy to catch up with your actions, instead of playing by his rules. So, the enemy either sacrifices a spell/hero power and some of his mana to deal that 1 damage, sacrifices 3 health on a monster (because your minion will attack back when attacked), or doesn't react and the next turn the Wolfrider deals his 3 damage AGAIN. Thus charge was proven too powerful for possible epic cards like [3/5/1 charge] or anything like that.
2. Early on, damaging spells were worse (they were eventually buffed to their current state), as a minion for the same mana was more useful. That's why now spells need more damage than mana cost, bonuses like Effect on spell cast/Spell Power are keeping them up with minions, and Mage minions give and get further bonuses to spells. Even now, Shadow Bolt is arguable instead of Wolfrider (especially when comboed with Power Overwhelming).
3. Let's talk about the Fireside duel. This game was totally staged to happen the way it did. The main idea was to leave the warlock at as low health as possible, and then turn the tables with Jaraxxus. Such clutch plays are very exciting for the viewers, and it was planned from the start to show this in the duel to hook as many people to the game as possible. While it's logical to advertise any product with the best it is capable of being like, this here was ridiculous - in reality the druid could win easily, but was not playing serious at all, because the warlock had to be the star of the video. (UPDATE: After seeing the strength of a Druid, do you now see what I meant? :) ). If the druid actually wanted to win, he wouldn't focus so much damage at Warlock's health only to leave him with 1 left. He also had very good cards in his hand that he didn't use at all to not counter the warlock too much. Just look at it, at some point he constantly had 7 cards in hand and didn't make much play with them. But that's why the team decided to use a druid against the warlock, druid has a lot of spells that make him draw cards. With a lot of cards in hand, the options you have allow the game to be much more easily controlled in the wanted direction. The idea of having as much draw as possible was why the druid had a Gadgetzan Auctioneer in his deck along with Nourish, Wrath and Ancient of Lore. And the intention to play Jaraxxus was why the warlock didn't activate one of his minions that discard a random card from your hand until later when Jaraxxus was already used.
4. There is a good reason you don't get free card packs early on when you start playing the game for the first time. Even though there is no trading, if you could get a free pack in the first 5 minutes of the game, this would lead to Chinese farmers and botting programs constantly creating new accounts and opening packs for the chances of legendaries/gold cards. Accounts would then be sold to competitive players or collectors. A fresh new account that had the extreme luck of finding 2 gold cards in its first card pack would often be sold to collectors who want such good start to building their full collections - a lot of them would pay the price to get this early big boost, instead of relying on RNG or disenchanting so much cards.
5. Some time ago all of you thought Shamans could summon three different totems - Stoneclaw, Healing and Searing totem. Maybe some of you remember that when I told you about the spellpower shaman totem (and then the second time when I mentioned it) I referred to it as "The third shaman totem" instead of "Searing Totem". Well, that was.... because it wasn't Searing Totem, duh. You may recall that I initially gave you a different version of the Earth Elemental, which was in fact summoning that totem. The idea was later scrapped and those two totems were put again on a test phase before solidifying them as a part of the Shaman's hero power arsenal (even though Searing Totem was made just a bland copy of the Paladin hero power). There is actually a proof of the totem differences in the earlier stages of the game - look at the Mage vs Shaman duel again, now that you know the totems are four. The shaman uses his hero power 6 times, and all 6 times he gets either a Healing Totem, or a Stoneclaw Totem. This is not some mad luck, the other two totems just didn't exist in the game at that time!
V. OBSOLETE LEAKS
1. Deathwing's latest version is the one with 8/8 stats, the 12/12 is too gamechanging and is an older version.
(The above is obsolete because Deathwing was reverted to his previous state, so now he's again a 12/12.)
2. Arcane Intellect is a bad card, as 3 mana for 2 draws is not a good deal. You'd be better by adding another strong card in the place of Arcane Intellect.
(The above is obsolete because it was true in the earlier stages of Hearthstone, where a single game lasted 7-8 turns (and back then, terms like "lategame" didn't mean the same as now). Later in development, games became longer and draw power cards like this one are now much more useful in the later turns. )
3. Additional generic cards are being made to combat the repetitive feeling of getting a single crap card from packs again and again. The idea is that getting three different useless cards will feel better than getting the same bad card three times.
(The above is obsolete because there was a change in direction. Early on boosters had a higher chance of giving you a common card. This was good for slowing the pace at which you build your collection, but eventually discourages buying packs with money as a purchase is not beneficial enough. That's why no additional common cards were made and there is even a rule now that every opened pack contains at least one epic/legendary card - to encourage buying them. The slow in progress was achieved by other methods - you obtain your free basic cards slower than before, and crafting was also made less effective.
4. I mentioned attempts for a Warrior Murloc deck, but back then murloc decks were weaker, and the Warrior spell "Charge" worked on all your minions instead of a single one.
FINAL WORDS: I'd say HearthPwn suddenly showing all the other cards was a bad thing. I gave you information about only the boring cards as I wanted the community to see the whole card list bit by bit and didn't want to screw up Blizzard by leaking a really cool card. Some of the cards especially would have been much more awesome for you if they were first seen in a Fireside Duel instead of a datamined gallery. But times change and I'm no longer needed. I could have still answered some questions about game mechanics, but Phenteo / Zeriyah are doing a good job on that, and of course people can fully trust what they say unlike me (even though I tried to build trust in myself as much as I can, maybe indeed looking too desperate in the process). But hey, a time when I would be useful can come again... See you at the Hearthstone Board!