I stayed away from outlands when TBC came out and leveled a belf mage (mainly to see the starting area). After she hit 60, I took my main at the time to outlands, and it had died way down. I'm doing the same now with a Deathknight, just singleboxing, and --whoa-- are they fun. My shammies haven't even been logged on for a few days now, but I'll hit Northrend probably next week or two, maybe it'll have died down.