I ground most of 73 doing a circuit in The Nexus. The nice side effect is a decent haul in Frostweave, Borean Leather and a few herbs to boot. Zone in, clear the 5 Dragonkin in the "diamond" then grab the large tree on the right side of the diamond (add the elite group if you wish), then the Mage + Dogs on the other side. That should take you around 7-10 mins and net you nearly 40K xp, all at very little risk. This works out to roughly 200K/hour, which isn't phenomenal, but it ain't bad. And, like I mentioned, it provides a few mats for your professions.

(edit: fixed my math)