I have...
Human pally
BE hunter
NE Druid
Panda(h) monk
Draenei Shaman
Goblin Warrior
Gnome Priest
Orc Warlock
Going to use my WoD boost on a Mage, probably BE, and make my hunter an undead.
I want a Dwarf, but don't know what class. Maybe do a bit of a swapsies, have Shaman dwarf, rogue human and pally draenei.
I make my decisions based on what I think each race is coolest as class wise.
I'm not overly concerned with what faction, although, Horde are pricks in world pvp. Rarely is it 1v1 with them, they gang up and roam around together. Alliance are usually on their own, doing things.