If you read the Wikipedia article (which I'm sure most of you have if you want to know about this game), you'll find that the main game mechanic seems to be a sort of "juggernaut" style of play, with one person playing as the protagonist and everyone else as enemies that are trying to stop him from completing the game.
Now, I'm absolutely in favor of radical new game ideas, but this one will be hard to pull off. What if the protagonist has to leave the game early? We hardly notice things this when it happens in normal multiplayer rounds, but in this case it'd ruin the game for everyone else. Then there's also the problem of you being stuck as an enemy in the game most of the time when you join a server, even if you put the game in wanting to play the protagonist.
On the other hand, this game could really strike a nice blend for some people. I, for instance, like the style of single-player gaming, but I prefer multiplayer games just because I like having other people there--whether I'm communicating with them or not, whether I'm getting pummeled by them or not, I just like playing with or against other people. So if I could get the wholesomeness of a single-player gaming experience and the community feel of multiplayer, that'd be neat.
Oh, and if I find out this game will have stealth missions, I'll have to change my opinion and my pants.