Not sure about this. Given how long the 360 and PS3 have been out now, with lots of online shooters, etc. I'm guessing there can't be that many people sitting around for whom this game will provide the tipping point.
At this stage I more see MAG as a good game to keep PS3 weekly sales at a decent level of demand and keep people who like a certain genre interested in the console.
Still, we'll see soon enough.
Try to be reasonable... its easier than you think...