With the gates having opened yesterday or today, depending on which side of the Atlantic you're on, guild are starting to test their might against Kil'jaeden. In this video VANQUISH, of Cho'gall (US), shows an early attempt at KJ. They deliberately showed us a try where they didn't know much, to avoid giving spoilers; nonetheless, of course, if you don't want to know anything about the fight, this is not the video for you.
Although it's pretty hard to tell what's going on, it certainly looks epic. Reminds me a bit of Ragnaros, actually. And it seemed to be going pretty well for Vanquish, at least until a small dragon showed up and everybody wiped -- except for one craft rogue player of some sort. Jeez. Good luck to all guilds trying to down him!