Blizzard's new MMO
We haven't announced anything on the new project. We probably won't for awhile. (Source)

Game design teams and forums

• 1) Kalgan is still here on WoW. We discuss the game design every single day. He is behind all of the changes we make.
• 2) The design team makes all of our decisions by consensus. It's a slow process, but it means there are no I-told-you-sos down the road. That portion of the team that doesn't post here doesn't get enough credit for all of the enormous contributions that they make. It kind of sucks.
• 3) The WoW forums have a storied tradition of attacking the messenger when they don't like the message. When Kalgan posted a lot, players attacked him too. Whether it's me or someone else posting here two or whenever years from now, they will become the new most hated person in WoW.
• 4) We don't let it bother us. You can't in this business. It's important to us to communicate with the players, and the forums are one way to do that. We just ban the players that can't control themselves and like to spew garbage instead of discussing the game.

Raids & Dungeons
"What's the point of 10-Man Hard Mode? Almost all the serious raiders are in 25-Man"
We actually don't know if this is true or not. Or more specifically, there were 40 player guilds in vanilla because that's all we offered. Then there were 25 player guilds for BC because that's all we offered. We had a lot of data and feedback that there are a lot of players who would prefer to run with a smaller group of friends even if the content was very challenging. As I said, we will see if 10 player guilds are more casual or if there are a lot of 10 player guilds who are up to hardcore challenges. (Source)

Naxxramas difficulty
Knowing what we know now, I'd hazard to guess that we would make Naxx 25 (and definitely Sarth 25) more difficult if we could do it over again, as well as dropping less loot per boss. But our model remains that the first tier of raiding should not be a brick wall for the majority of guilds who want to raid. Thaddius, 4H, Saph and KT are a lot more difficult for the average pug than the rest of Naxx. Maybe they should have been the model for all the bosses so that groups weren't surprised when they killed Anub'Rekhan on the first or second attempt. But, again, if you like wiping and wiping before you finally manage the kill, there will be plenty of chances for that in Ulduar and Icecrown. (Source)

Raid composition in Ulduar
Nah, I think you are looking at two extremes: trivial content vs. raid stacking. The cutting-edge guilds who have tried Ulduar so far had a really good mix of classes. Will there be more complaints (legit and QQ) about Ulduar balance? Absolutely. But we think it is a lot closer than it was in BT or Sunwell. DPS, tanking and healing are all closer and the raid buff design doesn't encourage stacking nearly to the BC degree. (Source)

Trash Mobs
Strong raiding guilds care about trash. Trash can still wipe you, especially in Ulduar. TK trash was harder than a couple of the bosses. If you clear trash slowly, you might fail a speed run or fail to get one more shot on a boss that night. I can understand how a character who sucks at bosses but excels at trash would not be attractive. But trash matters. If it didn't, we wouldn't include it. (Source)

Multi-boxing in raids
The number of multi-boxers is trivial. If you are a hardcore player you may know several of them, but in the grand scheme there are very few people really doing that.

If you want to discuss parts of the game that disappoint you, that's something I am interested in. Trying to argue that the metrics by which the business success of WoW is measured are somehow specious is a waste of your time. WoW is doing very well -- better than it ever has. That doesn't mean we can't improve the experience, which is why I'm still here in this thread. (Source)

Death Knight (3.1 Skills List / 3.1 Talent + Glyph Calc.)
Tanking nerfed in 3.1
DKs were too good on Sartharion, but that wasn't the intent and we nerfed them. Will they have a slight advantage on some fights? Probably. That will be true of other tanks as well. Do we expect most raids to tank with a DK? No. (Source)

Druid (3.1 Skills List / 3.1 Talent + Glyph Calc.)
Druid original design
I understand what you're trying to say with that last part, but the truth is our original design was that if druids want to raid, they have to heal. Our BC design was okay, you can try and raid with the other druid specs, but you are going to be inferior to other classes in tanking, casting or melee dps. We heard from plenty of druids who thought that was a terrible design and over time we decided we agreed and changed our vision for how raiding works. (Source)

Mage (3.1 Skills List / 3.1 Talent + Glyph Calc.)
Frost Mage in PvE
We think Frost mage PvE dps is still probably too low. (Source)

Rogue (3.1 Skills List / 3.1 Talent + Glyph Calc.)
Backstab Glyph in 3.1
There was a bug that happened between the Backstab glyph and the Dirty Deeds talent. This bug caused all damage, not just Backstab, to do extra damage to stunned targets. This was not the intent.

However, we had been balancing Subtelty for the last few weeks around damage numbers inflated by this bug. We realized when we fixed the bug that Subtelty dps might drop too much. To try and prevent that from happening, we buffed the bonus damage of Sinister Calling.

Rogue talents can be pretty complicated on the developer side. Often one talent has to have a special case to handle the effects of another talent. It is sometimes difficult to detect the bugs that are caused by two talents (or glyphs or set bonuses or buffs or whatever) acting in tandem.

Hope that explains it.

Are the developers aware that Sub is not the only tree with inflated numbers due to this bug?

Yeah. That was the problem. We nerfed Mutilate on purpose. This wasn't supposed to "fix" it.

We didn't attempt to compensate Subtelty for PvE because not many of them should have been running with the Backstab glyph for PvE unless you are really struggling with trash for some reason.

Some rogues do use Subtelty for PvP. As I've said before, it seems more popular in Europe and Asia than in North America. One article I read suggested that the build is super-dependent on coordination with your team members and tried to make some kind of cultural connection to that playstyle, but I get uncomfortable trying to characterize people that broadly. (Source)