If your uber guild has freed Kalecgos, beaten Brutallus, and felled Felmyst, and you've been a little bored, here's some good news for you: Agamath, The first Sunwell Plateau gate is now opened. This means that the Eredar Twins, Grand Warlock Alythess and Lady Sacrolash, are now fair game. Good luck to all the guilds aiming for a world first!
This puts the first gate opening time at just about 2 weeks (the patch went live on March 25th, as you recall). If the next two gates come down just as fast, we may see a world first Kil'jaedan kill somewhere around early May. Then again, I imagine Blizzard wants to drag stuff out just a tiny bit so that they don't need to put out a patch 2.5 with new content between now and the release of Wrath of the Lich King.