DRUIDS FTW!!
They DPS like crazy. They can Kite just as or if better then a Hunter can. They can great healing bots. Did I mention they can TANK as well. Pfft no need to play any other class.
<bubble burst>
-- Shamans can kite better yet.
-- Yes, Druid's heals are awesome, but they're also hugely mana inefficient (especially Regrowth). They also have relatively low mana pools.
-- They sure as hell can DPS, but in PvE, it's nothing compared to casters or Rogues. I don't think I've ever heard of a PvE DPS Druids...
-- Yeah, they can tank very well. However, due to the lack of top end (AQ, Naxx) gear that is intended for bearform tanks, they'll never match up to Warriors. Also, don't they lack a primary high aggro ability, such as Sunder Armor? I'm not familiar with Druid's abilities, so you'll have to excuse my ignorance.
</bubble burst>
If they're going to try and bounce around in different forms to accomplish different things (while maintaining the same spec), I think Druids are much more viable in PvP.