IGN has the goods on a TGS-related report on multiplatform trends from a Japanese investment research company called Morningstar. Apparently some Konami public relationist was asked about Metal Gear Solid 4 on the Xbox 360, and this person is quoted with "we're actively looking into a release for the Xbox 360."
So consider the whole MGS4/360 rumor thing back on, I guess.
IGN goes on to talk about the hurdles in putting the large Blu-Ray game onto several Xbox 360 discs. Perhaps everyone has forgotten that as of 11/19, we'll all be able to install Xbox 360 games to our 360's hard drive. While slapping a fat "requires 60GB or 120GB hard drive" logo on the back of the box would probably deter a lot of people, it would solve the problem. That said, a disc swap at every act or so wouldn't be that punishing, either.