I think it looks fun. At least co-op is quality, judging from 360 demo. It'll be dead in no time, but it feels like a well realized co-op game like Left 4 Dead, and not Mass Effect 3 multiplayer. Not to say ME3 multiplayer is bad, just that it's safest possible way to include multiplayer.
Not buying it now because I still haven't played Crysis 2 (which I own) and Bulletstorm (which I own) and other 2011 shooters (a couple that I own) I'll get too first.