To clarify how I will be leveling, I'm running around with warlocks and shadow priests, and dotting everything to death. The goal is to be killing non-stop. I won't be spending much (if any) time in instances. Each time I pause to loot a corpse, I'm delaying leveling. The sooner they hit 70, the sooner I can start making real gold. Consider how much /played time it would take to loot every corpse from 1-50, and even if you do great at the AH, your can just jump on the 70s, do a few dailies, and you've made more gold than you possibly could while leveling.

I still don't know what I'll end up looting.