They will. For all the whining on the forums, the fact that out of the 30 people i know playing, only 2 had something negative to say about it speaks volumes. WoW will remain top dog right now, but now it has a competitor. One with a strong IP, an accomplished developer, and a large fanbase. We may see that crown change hands in a couple years, but until one is shut down, there is plenty of room for both.