Comedy
Did The Matrix Online do badly because of WoW ? erm, no, it did badly cos it was pants, unfinished, unpolished, badly balanced
Did Street Figher or Mortal Combat break the fighting genre ? erm, no, it made it better.
Why did WoW do so much better than X ? a couple of reasons I'd suggest, 1) It's by Blizzard who have a long history of quality products 2) It involved many people who'd been vocally against EQ/Sony and so other knew some of the errors and mistakes wouldn't happen in WoW
Is WoW perfect ? Erm, no, it's just another step in the right direction, and for Sony to suggest Blizzard may be bad for the industry after there "swipe credit card here" servers is comical.
As far as long term subscriptions I don't think in 6 months anything will be along to displace that many people, what WoW has is a large group of casual players as well as the power gamers, and while there will be the normal ebbing of players from such a game it'll I'd assume be a larger number of power gamers/players than those casual one's, and then maybe others will realise that casual gamers are the ones you want to keep and please.
I'd still love to see numbers of players and there play times i.e
1 - 5 hours a week - 300,000
5 - 10 hours a week - 250,000
etc
etc
But I think I'd need to be fairly high level in Blizzard to ever see those numbers