Stay in Uldum until 84 and then move to Twilight Highlands once you hit 84.
Edit: If you haven't quested Deepholm yet, I would consider doing that. You essentially have to quest the entire zone to unlock the Therazane rep vendor, which you will need to get exalted with for the best shoulder enchants. You'll have to do it eventually so you may as well do it now while you still get experience for it.
For questing I really recommend getting the WoW pro addon. It tells you step by step what do to for questing an entire zone, and it's up-to-date with Cataclysm content.
http://wow-pro.com/addon