So now, two months from the end of 2009, let's just say it: it's not possible. World of Warcraft is an aberration, an extremely well-made game that happened to be in just the right time and place (the casual game explosion, the adoption of MMOs and subscription model gaming, the "mainstreaming" of fantasy/sci-fi geekiness) to become an uber megahit. In short, game developers simply can't recreate WoW, at least not on purpose. As BoJ says, that doesn't mean they can't try -- there are certainly lots of original and interesting games and MMOs out there, and it's completely possible to be an MMO that isn't WoW-sized and be successful. But as for the actual question of beating WoW and its worldwide audience, game developers have pretty much moved on.