My personal favorite, the priests. Bornakk drops in to let us know that Fear Ward is now able to be cast in Shadowform. This is small potatoes for the folks that don't play a shadow priest, but I can say that this is a pretty big deal. It'll be a great boon in PvP, and gone are the days of blowing my entire mana pool dropping in and out of Shadowform on Nightbane and Archimonde just for a Fear Ward.
Up next, mages! Blizzard stops the pain caused by battleground gluttons, by limiting the amount of manna biscuits you can carry from a snackwell to 80. As was pointed out by a mage friend of mine, this means you can't summon a table and carry extras around to hand out later, but I think this is the lesser of two evils.
Finally, warlocks will be able to summon party members into instances. No more standing around waiting for your buddy to get to the Black Temple from Goldshire, just summon away!