I don't know that anything's going to really unseat WOW until WOW2 comes out. Best a new MMO can hope for is to carve out a modest profitability as a niche experience.

Problem is, a large part of the appeal of an MMO is polish, and the community. Early MMOs uniformly lack polish AND community. Even with some compelling new mechanics and a good fiction, without the polish and community, people will just go straight back to WOW.

Someone may crack that nut eventually, but given the massive investment required and the ludicrous risk involved, and Blizzard's nearly infinite budget (which they can use to basically pummel you into oblivion, Starbucks-style), there's almost no compelling reason for a developer to compete directly with them.

Someone's gotta come up with what amounts to a new business model that exploits a similar socially-oriented game experience, but going toe-to-toe with Blizzard is financial suicide.

It's not as though this is a new occurrence. Blizzard games have always dominated the genres they took place in. Many Diablo clones and games borrowing elements of SC and WC came out and none of them really managed to come close to the level of success Blizzard had. The situation is only different this time because MMOs are such a risky endeavor. The few that do try to compete cost massive amounts of money to make and when they flop it's an equally massive disaster.

Developers can try to maximize their success against Blizzard by taking two things to heart. 1) Your game needs to have the scalability to play on a large variety of computers. If WoW player A thinks your game is awesome but his friend player B doesn't have a grand to blow on a new computer to play it, chances are player A is going to stick with the game his friends can actually play. See Everquest 2 as the perfect example of this.

Everquest 2 ran *poorly* on all but the biggest and newest machines when it came out, and it looked and played terrible for everyone else. This was done in the name of longevity: the game might look bad now, but 5 years later it would not require a graphics engine re-haul to compete with newer games. Focusing on making the game technically superior down the line instead of accessibly superior now put them in a bad position at launch that they never recovered from. The lesson here is to have games with an impressive level of style and atmosphere instead of a game with an impressive polygon count.

And 2), your game must offer something unique but not be a one-trick-pony. WoW continues to attract so many different types of people because it offers a little bit of everything to everyone. It's great if your game has a really unique focus that sets itself apart from competition like WoW, but other aspects of the game (be they pvp, pve, or social engineering) have to be covered as well. If your game has sweet pve but no pvp whatsoever (or a completely unsupported pvp system), it will not reach the wide appeal of a game li

continued: like WoW. People are less likely to attract their friends to it and therefor less likely to stay subscribed for a long amount of time.