There are other MMOFPS games out there. In fact, Planetside wasn't the first to do it. Project Visitor and World War II Online were the first two. Afterwards, Neocron came out but that game was largely a hybrid of FPS and MMORPG. As of right now, Planetside is the definitive MMOFPS, but that really doesn't say much of the genre.
The genre is still new and the big upcoming title is Huxley.
Look at all the typo and grammar errors on the official website NPC factions should NOT exist in MMOFPS games, it should be completely player driven Houses.... HOUSES... Why the hell do you need a house in a FPS? I don't want to waste time dinking around in a house, I want to spend that time out in the world shooting my enemies.
And the BIGGEST thing of all, it isn't a true MMO, it's just going to be an elaborate server driven FPS like counter strike, with a server cap of 120 players, 60v60.
Yes i dont quite get the concept of create servers to support massive amounts of players in one zone, claim to be an "MMOFPS" then instance all your combat, while taxing your players $15 a month, for what they will basically get playing on a UT3 RPG server.