Gamerlimit: "One might wonder what persuades a developer to offer their games on numerous consoles (or restrict them to one)? Another might wonder why all developers do not follow suit? See, there are multiple answers for these questions, both technical and financial. Having been in the gaming industry for about three years, working most of my time for Real Time World, (the developers of Crackdown), I have learned enough looking at both the technical and business side of this argument to understand why developers choose to have exclusives for particular franchises. Let's take a closer look."
Updates:
Why RPG's are exclusive.