Dinged level 72 last night (wee!). I logged with 15% vitality left. This is after starting at 0% vitality when the expansion came out. So I am basically gaining vitality faster then I can use it despite gaining two levels in less then 4 days... (I first logged into expansion on Friday of last week).
This shows you how quickly you can level by doing quests. Also, soloable mobs hardly touch your vitality.
In other words, just do the friggin quests! Its much more interesting then grinding mobs.
Save the vitality for grinding heriocs in Karnors Castle.