Mark and Sven are storming through the old world. They are up to level 55 now and this has been boosted by the Halloween event.
At level 50-ish they get 11-12K XP for each pumpkin quest they do, so I have spent quite some time this weekend touring Azeroth doing the pumpkin quests and also making sure to explore most regions for the Explorer achievement.
If I'd simply flown to each location and done the quest I would have finished a lot quicker. Hopefully they'll be high enough on level before Friday to do the Outlands one without having to 3 box escort them with EvilBastard.