I'm not sure I'm going to like MAG. The current Squad-on-Squad gamelay for most FPSs seems more practical because players are more in control of the action. I don't really trust other players to do their job right, so my greatest fear is being flanked because of an incompetent squad, and not being able to do anything about it. But I do like to keep my options open, so I will definitely try MAG.
I'll probably get BF 3 if I have a better PC by the time it comes out, or if BF 3 is multiplatform. But yeah, I BF 3 can definitely compete with MAG becausee BF franchise already has an established fan base.