I don't know about anyone else, but Outlands is beginning to ware. It was exciting and full of adventure when the land was new and I was still leveling up, but now I've completed many of the quests in the areas and I'm being hard pressed to find quests that don't require groups. So far the only area I have finished completly is Zangarmarsh, but I'm one quest away from finishing Nagrand and my only quests in Blade's Edge Mountains are the three group quests up in Ogri'la, and the dailys. I've been questing mostly for money for my epic flying, and so far I'm up to 1,444g.
So, hence my rant, I know when the new expansion comes out I'll certainly be ready to explore some new lands, although I'm not quite sure how I'll feel about the whole leveling thing once more. To be at 70 is to be at the top, and just like when Burning Crusade comes out, I'll once again be thrust to the bottom of the scale and have to level up to 80.
I'll also have to leave any epics I have behind to start off with greens, and eventually move on the blues, and then once I hit 80 I can start working on the epics again.
All in all I can tell it's going to be a lot of work, but if I get to experiance some new areas and content, then I think that will make it worth it.