People seem to run out of quests at around 64 3/4, and from there you've pretty much got to grind instances until 65 which opens up more quests.

I myself haven't gotten very far, the quest mobs on my server are being farmed like crazy, but they respawn like crazy too. I have to watch out because if everyone is in one spot and then moves, I've got like 4-5 mobs spawning around me. I was in that place where you get boiling blood and the little skeleton minion things were driving me NUTS.