So, I will be going with a Pally and 3 mages, however, the healer is a big debate. I love the fact that I've played wow for so long and leveled everything past 30 except Pally, Mage and Shammy. So this will be fun.

My Goals

Run every 5 man I can, even heriocs!

So, the priest provides a Stam and Spirit buff that the Shammy does not. However, the Shammy has its totems. Both can rez everyone and both have AOE heals. With 3 mages having 1 less squishy would be nice. So, taking all the known bosses into account, is it really that much difference having a Priest or Shammy as my main healer? I assume the Priest would have more mana as well, maybe not. Let me know what you think, especially if you have experience with a tank/3-DPS/healer combo.