Here's a video of Prince Kael'thas getting his ass served in his cozy new home, up on Sunwell Isle. This of course happened on the Public Test Realm, while the rest of us are waiting patiently (more or less) for Blizzard to deploy the 2.4 patch, one of these Wednesdays.
In case you've been living at the Auction House for the last couple of months, Kael'thas is the last boss from The Magister's Terrace, the new 5-man dungeon being introduced in World of Warcraft with version 2.4. You can read the tactics for this fight on Blizzplanet, if you really want to spoil the fun of an oblivious wipe. Not me, though. I got a challenge to attend with my guildies, to see who can clear out that place first, without reading tacts on the nets.