I'm not a big MMO player. In fact the only online multiplayer RPGs that I've played were Diablo, Phantasy Star Online (on the Dreamcast) and Too Human. Not exactly massively. I've been curious about EVE online since I love science fiction and that game seems to have a pretty good story and some gameplay mechanics but the huge time investment shied me away from it. Not to mention the monthly fees. Well I can probably just read the novel based on the game.
Unless an MMO based on Fallout comes out, I doubt I'll pick any of them up. However, this game, Infinity, looks particularly interesting. A space faring and terrain landing MMO that's supposed to feature a procedural universe and complete seamlessness between space and planet side. In addition to real time combat, unique storyline missions (no instances here!) and open ended gameplay, the small team of developers have a lot on their plate.
Even with their ambitious goals, they seem to have a lot going on. Hopefully they'll be able to keep the game going and release it at some point. The early videos they have so far are pretty amazing.