We will be making a change to the Pet Store such that pets purchased from the online store can only be claimed with World of Warcraft accounts registered to the region from which the purchase was made. In order to claim a pet from our Pet Store, your account must be registered to the same region as the store from which you purchased the pet. Players who have already purchased a pet from a store in one region and redeemed it on an account in a different region will remain unaffected by this change. Players on U.S. realms can access the U.S. Pet Store here: http://us.blizzard.com/store/

Then the good news is that, if you're able to patiently wait for patch 3.3 you will probably be rewarded with the very thing you're requesting. That's right, we aim to implement the ability to exchange bind-on-account items between your Horde and Alliance characters in patch 3.3. Of course, as with anything not yet live (and even things that are) this is subject to change, but it currently remains our intention. Hope that helps somewhat, or rather, hope that will help somewhat. ;-)

Emblems of Triumphs in Heroics in Patch 3.3
While we have changed the emblem system several times since the inception of badges of justice back in The Burning Crusade, we feel this is currently a good way to go so players aren't forced to run just old content like Naxxramas for 2 months to work their character/alt up to do higher/new content. (Source)

Tank mitigation and utility abilities
Assuming I'm understanding you correctly, we don't balance tank survivability around utility abilities like say Cleanse or Death Grip. We try to make sure all the classes have a certain number of those. We do balance survivability around cooldowns that affect survivability. My recent caution to not over-interpret effective health was that A) cooldowns matter, and B) it's difficult to quantify those cooldowns as part of EH. (Avoidance matters too. You may not gear for it, but it matters and you'd notice it if it was gone.)

I totally agree about the context part as well. I try and say often that the encounter is everything. Most of the time when players are posting from the point of view of who is the best tank or whether a certain tank is a liability to the raid, what they really mean is "on Sartharion +3, Mimiron hard, Vezax hard, Gormok hard or Anub'arak hard" because those are the most challenging encounters in which to keep a tank alive.

If Sindragosa is the hardest boss in Icecrown, and if she does a ton of magical damage, and if Unholy death knights have a much easier time tanking her because of this, then you'd see a lot of arguments over magical mitigation and cooldowns. (Source)

Onyxia Whelpling Pet
The Onyxia Whelpling pet will be available in-game soon, though I don't have an exact date offhand. If you login on a regular basis it should just appear in your mailbox sometime this month. (Source)

Paladin
Lay on Hands and Forbearance in 3.3
The change we're thinking about now is that LoH only causes Forbearance if you cast it on yourself. A paladin healing a paladin tank wouldn't run into the Forbearance problem.

We don't think the paladin tank needs to be able to stack both tools at once. If you know big damage is coming you can use Divine Protection. If you managed to take the big damage, you can use Lay on Hands. (Source)

Warlock
Infernal Cooldown Reduction
The problem with lowering the Doomguard cooldown to ~10 min is there is a reasonable chance Affliction would just use the Doomguard all the time.

We want the temporary warlock demons to useful but not actually replace the core demons. An interesting idea for Cataclysm is for them not to replace the current demon. I have no idea if we'll do this or not, but we won't be able to do it for 3.3.

[...] If you read the patch notes, you'll see that we lowered the cooldown on almost every long cooldown ability. The ones we did not lower (like the Doomguard) we didn't lower for specific reasons. This was not an attempt to buff Inferno and make it something all warlocks use. It was a pass at all of the long cooldowns still in the game. (Source)

Pets and Guardians
The way the current technology works is you can have one pet or many guardians. Pets have a pet bar and guardians do not. We get around the first limitation on group pets like the shaman wolves by having them both use the same pet bar.

It wouldn't be too hard to make a guardian Doomguard or Infernal pop out without replacing the Imp or Felhound etc. but then you'd lose the ability to give it specific commands. Having a second pet bar pop out or having one pet bar give different commands to different pets is something we currently can't do. (Source)

[...] I think there is some promise to the idea that warlocks might have permanent pets and guardians, with the Doomguard and Infernal as dps-timers in the second category, much like Force of Nature or Mirror Image. But we're going to have to think through that design and analyze the technical and balance implications. Maybe it will work and maybe it won't, but it isn't going to happen for 3.3. If you'd like, we can bump the Inferno cooldown back up if it bothers you so much. (Source)

Affliction Spec
We didn't like the way Affliction played. There were players who liked having so many dots and players who didn't. It certainly wasn't the case that whoever QQ'd the most won (and I suspect it was the pro dot crowd who QQ'd the most). We wanted to make Affliction more about the Shadow spells and Destruction more about the Fire spells. We wanted each to have a core group of spells upon which they focused. That is happening now and I believe both specs are fun to play. (Source)

Warrior
Mocking Blow "change" in latest PTR build
As several have pointed out, this was just a tooltip clarification. The ability hasn't changed.

I agree with the notion that there is less of a use for Mocking Blow in the toolbox these days where tanks generally maintain enough threat, at least relative to the "Wait for five Sunders" days. (Source)