Square just shot themselves in the foot.
I don't know how much the rest of you know about porting (I'm an expert), but releasing an inferior product on Xbox 360 goes completely against the natural order of things. It's not like it is in Bizarro Land where you can release multiplatform titles on PS3 with native 720p running at a stable 30fps. If you screw 360 over in our world, you are afronting the laws of physics, and the only way to restabilise them is repentance.
What this means is the fabric of reality, after the 360 version is released, is going to tear itself apart, allowing beasts of unfathomable horror to bleed through to our world. This is HUGE. You can laugh all you want, but Square has doomed us all with this move.
Square, publicly apologize and re-port FFXIII for 360 or we can kiss the universe good by.