Well u have a point but also great exclusives game released for ps3 so why would they buy an 1 year old port.
Personally i tryed the demo and it was good but it wouldnt buy beacuse there was simply better games release as well.
To sum up i defenitly think it will come to ps3 but like i said Micorsoft will probaly make sure that it is timed exclusive even if it is for a month.