I know a lot of people have said this won't be the case but if the first 6 or so months aren't the success that they expected to be then I don't think they'll keep the monthly fee model in the future or at least, they'll charge less.
I definitely think the game has potential, I'm sure you get a month free with the game so that's one thing. For us console gamers, if you're not hooked by then you can sell the game on.