I've got a five priest group.
Just leveling very slowly with the Grizzly Hills dailies, as that will get them to 75th before Cataclysm.
And they're not a main team, just a set of alchemists.

However, they are quite fun, and of my alchemical teams they're by far the most likely to actually reach 85th.
PW: Barrier, PW: Shield, Holy Nova, Smite-Healing, Penance for DPS, Mass Dispel & Fear Ward on round-robin..
5x SW: Pain, Devouring Plague, Shadow Fiend, Mana Burn, SW: Death...

A lot of fun with them.