Shaman
Spirit Wolves pet action bars issues (spells casted twice, settings not being saved between summons)
Unfortunately, this is just the way pet bars work. If you recall, we resisted even putting bars on temporary pets for a long time because the system wasn't designed to work that way. We do have plans to fix it, but it requires new code, and we didn't think it was worth holding the release of the expansion until we got this changed.
Elemental tree balancing and lack of AOE
We have spent more time on Elemental over the past few days than maybe any other spec (I know that quote is going to come back to haunt me). We want to make sure the spells are doing what they're supposed to at 70 and 80. We do think fire makes all the difference at 80, but we're going to go back and make sure that opinion is grounded.
One concern that I think is legitimate and that we would like to fix is Elemental's lack of AE. We realize that players will likely compare Elemental to warlocks and mages. Since Elemental isn't going to do higher single target dps than those casters, it's pretty crummy for Elemental's AE to be so dreadfully below theirs.
Warlock
Soul Shards
We like the mechanic of having to harvest a special reagent for some spells. We don't even think the spells are a big problem, with the possible exception of summoning a lot of people (and we are working on an idea for that last part).
Where shards really fall down IMHO is in the inventory management. We want them to be limited, but the way we handle that now feels a little old school, like inventory Tetris in Diablo. We do have a few ideas on how we want to fix it, but obviously I don't have a big announcement to make on the subject yet or I would have made it already.
Warrior
Protection Tree and DPS warriors
We're happy with the state of Prot now and even happier that warriors seem to like the spec. But I don't want to leave the impression it's because Prot warriors argued for changes in the right way or somehow whined correctly.
One of our goals coming into LK was to "fix" tanking. This included a lot of changes.
Making sure threat wasn't so frustrating, especially AE threat
Making sure all 4 tanks could handle the same encounters
Make sure tanks who were missing key tools got them (I realize the word "key" is open to interpretation)
Making sure tanks could upgrade their gear in a reasonable fashion
Making sure tanks didn't have to spend all of their talents on pure mitigation
Making sure tanks weren't so terrible in PvP or solo situations
By contrast, the dps specs didn't feel broken overall, although there were individual problems with many of them that we did attempt to address. DPS was something fun in the game that continues to attract a lot of different players and classes.
With regard to dps warriors, a few of these changes were:
Make sure they could tank a normal 5-player dungeon
Give them both viable PvE and PvP roles
Make the Arms tree about something other than Mortal Strike
Make Battle Stance a little sexier
Make sure mobilty didn't just belong to one spec
Try and get warriors to care more about plate
Make warriors a little less reliant on "pocket healers"