PS3 offers great FP Shooters, so the reason to buy a Xbox 360 "because it has Halo" doesnt work any more imo.
But no exclusive shooter for Playstation will ever (or at least for a long time) achieve Halo sales figures.
Wenn killerspieler in killerspielen killerspieler killen, dann killen killerspieler in killerspielen killerspieler.