So far aside from WoW which has generally conceded any dignity that it ever had, Tera has been pretty solid in my opinion. It's a little slim on content for the moment but the gameplay is fun and HM Auricadis and HM Kelsaik are challenging fights on equal ground with the majority of hardmode WoW raid fights (and significantly harder than any of the 5 man content in WoW obviously).
Before this last week, GW2 was having a somewhat mediocre beta and losing hype fairly steadily, but now that it's been sold off to Nexon, a lot of what would have been its post-release player base has forsaken the game. It's largely dead in the water and the only people I still see really pinning hopes on the game are the most dedicated fanboys to the series. Hopefully GW2 isn't a flop when it comes out, but the fact that it's losing steam while in beta without even a release date yet and the fact that it's been sold off to a company that is notorious for turning games into pay-to-win disasters that die off completely in a short time, is not boding well for the game.
Other potential MMO's in the near future are Blade and Soul, Neverwinter and The Secret World. Unfortunately, Blade and Soul is very very very eastern so if that isn't your thing, you're SOL. Neverwinter is being described as a "multiplayer online rpg" so you can discern whatever you want from that. And lastly, The Secret World is being handled by the same people that released the half finished disaster that was Age of Conan. Of these 3, The Secret World's premise is probably the most ambitious, but Blade and Soul has similar gameplay to Tera which benefits it, even if the game will very likely be slim on content upon release.
Draw any conclusions that you want to from all of that.