Do you think that WoW will kill the userbase of some (if not most) of the today's MMORPGs?
Blizzard is a very popular and competent developer, their games are very well made and this is much more than you can say about many MMORPGs released these days.
Considering that most players didn't have the money and the time to have more than one paid account on these games, I think that the migration of people to this new RPG can be a hard issue to old games. What do you think?