I think for Cata I am going to change my playstyle a bit.
Instead of leveling my 80 warlock and playing the new endgame, I think I am going to level a brand new character, WITHOUT heirlooms (but I'll give him gold to buy large bags only), and take my good old Texan time leveling him. And by that I mean not care at all about experience effeciency or getting to 85 as fast as I can. I am going to play the game in an extremely casual way. Quest everywhere, whether it gives me XP or not. Go for Loremaster right from the start. Read every quest. Explore every place. Run every single instance along the way. Take time to PvP in battlegrounds while I level. Go sightseeing. Some nights I might not gain any XP at all, but I'm going to be okay with that because my goal will not be getting to 85. My goal will be having fun exploring a world and relaxing while doing it.
And when I do get to 85 it will be a long, full journey getting there. Probably months from now, at least half a year I'd say.
Now I just have to decide what character to roll for this epic journey. Goblin rogue sounds fun, I've never seriously played a rogue. Or a Troll druid. A Tauren priest would be interesting, something about a holy cow in cloth armor would really be a change for sure. A Tauren paladin is also appealing.
I mean, the new zones aren't going anywhere, they will still be there a year from now. Heck, they will most likely be better a year from now after tweaking and bug fixes.
Something about this idea sounds refreshing to me.