On your main server anyway.
So what character, in what order etc.
For me:
Level 85 female Orc Hunter, my one and only main.
Level 80 female Undead Priest, currently in shabby PvP gear and I think still without specs.
Level 62 male Tauren Warrior, half naked because all his shiny heirlooms went to my paladin
level 80 male Troll Shaman, currently elemental.
Level 80 female Tauren Druid, feral and in ICC gear
Level 45 female Blood elf Rogue, with shiny heirlooms and everything.
Level 28 male Undead Warlock, half naked because all his heirlooms are worn by my mage.
Level 73 female Orc Death knight, also half naked because I only have one set of plate heirlooms :P
Level 63 female Blood elf Paladin, prot and the next toon I'm taking to 85 (unless I change my mind)
Level 6 male Goblin Mage, very very very slowly looking around the new Goblin starter area with this guy. Although I've never liked mages it's the only class I didn't yet have one of.
So yeah, only 3 characters left with whom I can play around in the old world, 2 I still have to drag through Outlands and Northrend and 1 just through Northrend (thank god all 3 are tanks, yay for instaqueue!)
But with my hunter having Cata Loremaster, I'm not too eager to go do the new zones again.