In every other computer game but WoW, I've tended to pick the casters. Sorceress in Diablo 2, mage, wizard, all that stuff.
I didn't pick a mage in WoW (mainly because of Sylvanas Windrunner), and really, hunters aren't all that different - they use mana, they're ranged... but until now, they never had any decent AoE.
...I'm really hoping Blizzard doesn't nerf Volley until I finish AoEing through all the low-level instances.
(Also.... running a BT PuG and ending up #1 DPS over the mages and druids - we didn't have any warlocks - by a good 1% while spamming Volley was absolutely hilarious, considering I don't have the best gear. Enjoy it while you can! :D)