Originally Posted by
Anoregon
You have never needed previous expansion epics to level successfully in the beginning of the new expansion. However, you could start the new zones two levels earlier than the previous max (58 for outland, 68 for northrend) so it wouldn't have really been possible to level in hellfire at 58 if it required lvl 60 greens.
Cataclysm is a bit different in that the two starter zones are tuned for level 80 instead of 78, but you should still be fine without accumulating any epics ahead of time. I mean, think about all the goblins, worgen, and assorted new characters that are going to be coming up soon. With no one raiding Icecrown anymore, how could they be expected to get level 80 epics before venturing into Hyjal?