I'm sorry, but two failing games are going to make a comeback in 2010: Age of Conan and Warhammer Online. Both of these games are fairly fun. AoC is coming up with interesting new content. Warhammer Online has done great work on their client and game mechanics, it should also make a resurgence under new direction.

SWTOR and Allods will be big, f2p will continue as always with some of the crappier old games dying, and the big surprise will be Guild Wars 2 releasing in Q4 2010! :D