First off i reember alot of people telling me that you have to be 80 before you can go to the new zones, and by my lack of activity on the internets latly i just found out that hyjal is a 78-82 zone, so yaaaay! no more icecrown for my alts that get level during cata!
Also to the people that said you wont be able to do cata zones at 78 you need to be 80....shame on you! shame...