I've been wondering about that. In my mind, it's best to do all the pre-60 quests of Azeroth, in order to save as many quests as possible in Hellfire for leveling beyond 60 - because in Outland most of your leveling will be done by emptying zone after zone of quests. Since the only characters I've ever entered outland with were all level 60 well before the expansion, I don't actually know if that's true or not. And I recently started an alt to play when I don't have the time to log on to my main. It's only lvl 9, and it won't hit 60 for a long, long, long time but it renewed my interest in the idea behind staying in Azeroth for as long as possible. Any thoughts now that you're in that leveling frame? Do it, and try to save as many of the "last in the chain" quests (or even the last few) for after 70, because of the money rewards. A friend of mine recently got a second shammy to 70 (he rerolled a shammy so he could have one dps and one healy, lol) and used this method, and he was on a flying mount within a day because of it.