Well, I am only level 6 atm, but I plan on going Balance on a Druid, Destruction on a Warlock, Arcane on a mage(Curse of Shadows) and then Restoration on my shaman and then a prot warrior tank.
Seems like a well made group to me, I didn't want to play a priest because I already have one at 70... so meh. I will more than likely switch the specs on the druid and shaman post 50 sometime, tree druids are just all kinds of hawtsecks.