Curse reports that Forte from EU Kazzak took out Anetheron in Mount Hyjal on Saturday evening, winning them the world first on that one. Then, on Sunday, Nilhilum (on EU Magtheridon) and Curse (on EU Vek-nilash) both headed into Hyjal, and downed Anetheron and Kaz'rogal-- and this time, Curse picked up the world first on Kaz.
MMO Champion has more, including deets on all the kills (and the fact that Curse also picked up Supremus and High Warlord Naj'entus in the Black Temple-- with only 22 players in the raid!), and screenshots for every kill. So grats to Curse, Forte and especially Nihilum on all their achievements this weekend.
What does all this mean for us casual players? While usually a world first kill means not much more than a tip of the hat, so many kills like this in one weekend might be a sign that Blizzard is getting serious about making the endgame more friendly to casual players. If these hardcore guilds can burn through this content so quickly, it's probably not long before we see more casual guilds moving up the ladder behind them, right?