Now we're to my favorite part of a new patch -- sussing out the undocumented changes. Everyone's really known about the patch notes for months, but it seems like every time Blizzard releases an update, there are always plenty of undocumented changes that don't quite make it in.
WorldofWar.net has a good set of changes so far: Troll offhands are small, Gruul's Lair's and Kara's reset display is off, and Shamans' Mental Quickness talent doesn't seem to be working. A few people have already noticed that there is no repair character on the Isle of Quel'danas yet, but that's only because the daily quests haven't moved forward yet -- with a bigger foothold, the Shattered Sun should be able to bring in a blacksmith or two.
Void Reaver seems to have been buffed a bit, the Shaman clearcasting ding is bugged, and I've heard that the Blood Elf mounts (a.k.a. Chocobos) will now squawk on demand (though I'm not sure that's new). Seen any other undocumented changes on the realms yet?