Tonight, <Goon Squad>, Mal'Ganis, killed Hardmode Tirion Fordring in the 10 man version of Icecrown Citidel. This is the world first kill, and caps a long tradition of Goon Squad killing the major friendly faction leader of each expansion. Here are screenshots and a video.
http://www.youtube.com/watch?v=onWY4Q0hIjU
official forums thread: http://forums.worldofwarcraft.com/th...597181&sid=1#1