I would want too and would guess, as we have barb, druid and sorc so far
* paladin/crusader/deathknight
* ranger
* necromancer/warlock
As then we will get 3 melee, 3 ranged... I love necro with pet build, but same time I would want too see necro goes more to a death knight approch and then we get a warlock instead
But sametime I would love too see priest - full support character too