J. Allen Brack and Tom Chilton answered questions from fans about patch 4.03a and Cataclysm.

Sair77: The first tier of Cataclysm raiding has 3 seperate instances to tackle. Are you guys planning on keeping with the Burning Crusade model (SSC/TK, BT/Hyjal) and having multiple instances per raid tier? Will Deathwing have to share the spotlight with some other instance?
TomChil: We'll evaluate that on a tier by tier basis. When we have awesome ideas that we can successfully make happen we'll do multiple environments, but it won't necessarily always be the case. We do have a super cool idea for the deathwing tier though... or at least so we hope. =]

Zuesian: Are there any plans for a new Lock mount? I would love to see a possible flying mount for Locks. Fireion Gnomeragen.
JABrack: One of the things we look at with mounts is broad appeal. While we do specific class mounts from time to time, most of the time we look to have mounts that all classes can use. 

Arakiba: What happened with the Worgen district in Stormwind?
TomChil: We decided it didn't really fit very well, it was looking kind of awkwardly forced into the city. Plus deathwing would have destroyed it anwyays.
Dorothy-BBY: RAWR!!!

Guest-128: As the world of Azeroth is changing I was wondering if the Death Knight zone will stay the same or will it also be affected by the cataclysm?
JABrack: The death knight zone doesn't have any changes for Cataclysm. 

Guest-310: I have been confused from the different posts for tier gear. Will there be three levels within each tier still or just heroic and normal and in either case will u just be getting them with points or will u still have to get certain things off drops off certain bosses to get the higher more heroic version of the tier gear?
TomChil: There is still just normal and heroic difficulty for the raid and dungeon content, and the heroic gear has a higher item level than the corresponding normal gear

Guest-392: Do you feel faction imbalance is a problem at the moment? My queue is around 10-15 min at prime time as a member of the Horde and I know this is the case on at least two of the battlegroups. If so, do you think Worgen will fix the problem? And if they do not, will free faction changes ever be a possibility in the future on battlegroups or servers with a major problem?
JABrack: We are working on some technology to further combine the PVP queues at server sites. This has been going on behind the scenes for a few weeks now in preparation for Cataclysm. Queue time is one of those things that gets a lot of attention and time, but will change significantly post Cata. Really good question.

IanG: What would you say was the hardest and/or easiest parts of developing this expansion? After all, many are saying this is the best expansion to date... So, what was the biggest challenge/easiest feat in creating it?
JABrack: There have been huge challanges with this expansion, unlike any we've seen in the other two expansions. The scale of Cataclym is huge for us, and something we didn't really expect when we started development. But we certainly feel like the effort has been worth it, and feel it's our best expansion so far. 

Guest-202: Why does it seem the scorpion guild mount doesn't have a guild flag where the lion does? I was hoping to see Hordes of scorpions from our guild walking around with our tabard hanging from the tail like a flag behind them. ~ Sorenji of khaz modan
TomChil: When riding a scorpion mount, your character displays holding a large standard with your guild symbol on it. 

Guest-127: Why did you decide to make 310% mount speed purchasable in 4.0? It's a huge price for such a tiny speed upgrade, and used to work well as a just-above-vanity perk for people who completed the toughest achievements. 
JABrack: The primary reason was to equalize the awesome vanity mounts players had, and change the mechanic to one where you used the mount you were most excited about using. We wanted players to be able to see the mount players want, without considering the speed differential as a factor. 

Guest-411: Will you allow players to change their login screen? I'd love to be able to use the Classic login screen, the unreleased one that was shown at Blizzcon, or perhaps a login screen of a previous expansion.
JABrack: Players are not able to change their login screen.

barretrifle: How would a person get a Guild Mount? Would it be guild rep? If so how would that be calculated or obtained?
TomChil: Once your guild gets to a high enough level and unlocks the guild mount, any player in the guild with a high enough guild reputation is able to buy the mount.

gandclynn: Will heirloom items work for goblins and worgens leveling from 1-80 at release? 
JABrack: Heirloom items will work perfectly for Worgen and Goblin characters! Enjoy! 
Dorothy-BBY: Woot!

Guest-124: Has there been any discussion of changing the heirloom items to true "Bind on Account" instead of the bind on server limitation that it has currently?.
JABrack: That is something we would like to do. Currently the servers mail carriers refuse to work together, and haven't worked out the economic terms from transferring mail from one server to another. One day we hope to resolve the union issues. 

Wikehaja: Will the option ever be available to change ones class, contingent upon what's currently available to the race restrictions at the time?
TomChil: Never say never, but we don't currently have plans to do that. 

Guest-451: There's any through about making account wise achievement, like starcraft ones? It a reason for many players to not reroll/change mains since its look like a lot of work wasted when you switch your main char. Even changing to another char to help with one fight look a bit wrong now, if you are after achievements.
JABrack: We do have plans to solve this problem, as it is limiting people from re-rolling for sure. This is something we want to solve, but don't have a good solution on how to do it at the moment. 

Guest-314: Was there anything you guys regret not being able to include at launch? Possibly something that didn't have enough polish to it that me way see in the future? (You don't need to mention the Dance Studio at this point, really, it's okay) Teln - Misha
TomChil: Well... there is the dance studio. ;] There are of course always things we'd hoped to get into any patch/expansion that get pushed out until later. One example would be the idea to have a built-in atlas that details every encounter in each dungeon/raid. We're not super happy about the fact that the first time anyone encounters a new boss, the only way to learn about it (other than looking up strategies on the web) is to charge in and die a lot. 

We'd love to give players some idea of what they're about to fight before they engage the boss. =]

ZeroG56: Do honor points and Badges roll over into CATA, or do they reset to zero?
TomChil: Yes, honor points and justice points carry over into cataclysm. Stock up now!

Spyykke: Is there any talks of maybe some faction cooperative campaigns? Since the cataclysm is threatening to destroy all life of azeroth, to me a logical response from the heroes of azeroth would be to set aside their differences and be able to work together in a raid. An Idea to maybe lessen the frequency of such groups is make the raid difficulty increase by choosing to work with the other faction, a sort of Heroic mode. Possibly even dual faction specific raids. Has there been any talks of such poss...
JABrack: This is a common request, but not something we are looking to do. While there is a singular main bad guy in this expansion, the Horde and Alliance have their own unique challenges and agendas, and typically don't look to team up. After all it's the World of Warcraft, not the World of Peacecraft. 

Guest-87: When designing expansions and content patches, do you have a list of new features to choose from that are planned out in advance or is there more of a brain storm session?
TomChil: The feature set for each patch is determined by a combination of doing things (or finishing things) that we've been wanting to do for a while, along with completely new ideas that emerge as a result of the immediate needs of the game
JABrack: The primary things you won't be able to do if you don't have Cataclysm are create a new Goblin/Worgen, level to 85, and fly in the orld world.
TomChil: We like to stay as flexible as possible, so it's important to us to make sure that we aren't "over planned" into the future even though the real needs players have are changing

SirHaakon: With the previous two expansions, the new content was actually on other continents, so if you didn't have the expansion, you just couldn't visit the continent. Since Cata is largely reworking of old-world content, however, how do you differentiate between someone with or without the xpac? What kinds of things will and won't be available to players don't have the upgrade?
JABrack: See my answer above!

Guest-16: Will the 80 to 85 experience be closer to the 18hr mark or the 5 day mark that was 70-80? 
TomChil: That totally depends on the player to be honest, you'd be amazed by the differences in play patterns. That being said, somebody usually finds a way to level up very quickly.

Guest-348: What new feature(s) in WoW: Cataclysm are you guys most proud of?
TomChil: I would have to say the 1-60 revamp, it's a ton of fun to play through the zones and an incredible amount of new content.
JABrack: I'm most happy with the new Worgen and Goblin starting experiences. I think they are the best starting experience we've ever done, and that includes the death knight. 
Zarhym: I'm most proud of J. and Tom.

Guest-908: Question i have is why not have this latest expansion as a new territory like a Southrend similar to Northrend or a Moon body like Outlands instead of destroying Azeroth and Kalimdor? Were there limitations to expanding outwards or was this just to facelift the original game?
TomChil: We make decisions like this on a case by case basis.. again depending on the needs of the game. In the case of Cataclysm, the world was due in for an overhaul, and we wanted to make everything fly-able, so it was important to flesh out any areas that were originally unfinished.

Guest-441: Can you clarify and confirm what will be available to players when 4.0.3a hits and what will be unavailable until 7th Dec?
JABrack: 4.0.3a will be the patch that actually causes the world to shatter and change forever. At that point you will be able to experience the new 1-60 leveling experience, as well as the new race/class combinations. Very exciting!

milesd21: Is there an alternative mount for worgens that other races can ride 
TomChil: Worgen can ride the other mounts in the game, if that's what you're asking. They're not limited to their feral run.

mikewho3: With the level 1-80 Heirloom items, when Cataclysm is released will the xp gain work while leveling until you hit level 81? Or will XP gain be disabled for those on release?
JABrack: They will not. Heirlooms stop granting their XP bonus at level 80. Not level 80.9999999.

gandclynn: Will achievment points ever be able to be used to purchase any perks? 
JABrack: We have no plans to allow this. Achievements are a badge of honor only.