I really like centralized, minimalistic UIs. Remove useless clutter, especially for battles so that you can better focus on the action. That's another reason for the unit frames in the center of the screen, so that I can see what's going on without having to look away from the battle. Keep all of your abilities keybound and memorize them so that you don't need to dart your eyes around unnecessarily, and move them far enough away that you can still see a big enough portion of the screen while still being able to see your procs.

On the topic of UI's, I am really looking forward to addons. As much as people hate on WoW, it was one of the best features of the game IMO. The level of UI customization was incredible, and addons like PowerAuras and DoT trackers/timers were so, so very useful. I became hooked on centralized UIs when I began customizing my own UI, trying out different UI compilations that people had created, and eventually fell in love with RealUI, my absolute favorite and #1 must have UI compilation for myself.

Here is what it looked like: