Well, if we're to believe VGchartz, PS3 is been outselling 360 in NA week in, week out, so I think it's safe to say PS3's fate in NA looks kinda locked right now even before MGS4 debuts. After MGS4 it can only get better. I seriously doubt the Xbox 360 will be able to outsell the PS3 for a single month in NA at least until GoW2 debuts and we'll see what the future brings.