I can easily solo every boss in ZG on my Death Knight. The hardest one is tiger because you have to pay attention to the interupts.
I solo it on Ed and to be honest ... I don't give a [censored] about interrupts. Yes, it makes it go faster, but when you can pop berserk and spam maul (read: rollfuckingface) ... [censored] dies.
Outlands and Northrend will be unaffected from what I understand, obviously Northrend might change some since it resides IN the world ... Outlands does not and must be accessed via portal. The last notes I read said that Outlands and Northrend would be left alone as leveling zones so once can assume the raid instances will stay the same.
Everything on Kalimdor and the Eastern Kingdom is fair game for "wtf?"