I doubt it. They want people to keep playing and paying, so if it keeps ticking people would play in The Burning Crusade less :P

Personally, once you get finish all of the high-end instances I don't see how it stays interesting. Guild Wars gets a lot less fun once you effectivly finish the game, even though it is the most fun game :P I've been wondering around the Guild Wars world, workingon titles a bit but it is a lot less fun then Prophecies, Titan Quests, and Sorrow's Furnace were. I can't wait for Nightfall to come out.... I hope it has interesting features that will last until Chapter 4...