The number one complain about world bosses was always the fact that certain guilds had them on watch/farm, while everyone else could never kill them.

If the Phasing system thats will be used more in Cataclysm is powerfull enough to change the appearence of entire zones, could'nt Blizzard use it as a method to faseshift World Bosses too?

Yeah, I want world Bosses back badly...

There's a lot of stuff we could do in the game if we wanted to. The key thing here though is "if we wanted to". We often do things that players suggest, though; so if you want to suggest something that you'd like us to consider, please go ahead in the Suggestions forum:
http://forums.wow-europe.com/board.html?sid=1&forumId=10024

Thanks!