Okay, there's a LOT to go over, but I'm going to stick to the PvP-centric changes right now... I'll have more details as they come in:

* No new talents, but 5 more talent points to spend.
* Changing a lot of talents to be "more fun"
* Mastery System which will give passive bonuses as more talents points are spent IN a tree (more points in assassination tree? have some bonus crit value).
* "Path of Titans" character progression. Think "pet talent tree" but for your class, based on the path you choose. So, it's like picking "Druid of the Talon" when you're already a druid... except it's not class-based. Okay, that's confusing, interesting-but-confusing. I'll have more info as it comes.
* Worgen racial OP for arenas: Sprint
* Goblin racial OP for arenas: Blink