I have 1 Prot Paladin, 2 Ret Paladins, 1 Disc Priest and 1 Fire Mage.

I have the 2 rets follow strobe (using Jamba) the prot and the other two stand at range.

I like the mage for portals and crowd control (you might need this again in cata).

The priest only heals; I have transparent ISBoxer click bars set up over a healbot display on my prot which maps to mouse presses over healbot on my priest. Setup here (click bar part down where Lax posts): http://www.dual-boxing.com/showthread.php?t=30511