It's not coming to 360 anytime soon. If it were, they would have announced it at the Microsoft press conference. People were expecting MS to announce that MGS4 would be on 360, but they didn't. Besides, Kojima has stated many times that MGS4 is built from the ground up on PS3 and will not be on 360.
Core i5 2500K @ 4.8 GHz || 16 GBs 1600 MHz DDR3 || Sapphire Radeon HD 7970 || Dual 128 GB SSDs