WoW will be hard to take down
I like WoW for the social aspects. There are quite a few members of my family that play WoW - gals and guys both. We can do things alone, together, or just chat. WoW also puts serious skull sweat into making things fun for both the hardcore and the occasional gamer. They celebrate holidays, have carnivals, and don't take themselves too seriously. Blizzard is far from perfect, but they are better than anyone else right now. Eventually they will lose the MMO crown they took from Everquest, but it will take major screwups from them as well as a better game available. Just having a better game will not be enough to take their market share away.