Given the fact that the fourth game in the series is
poking fun at the 360's storage size, and that XBLA is well known for memory restrictions (
MGS was bigger than XBLA's limit of 350MB), this rumor doesn't seem too plausible does it? However, the original
Metal Gear Solid did find its way to a multitude of platforms and a version of the game (PC) was actually published by Microsoft.
According to Ripten, who say their source spotted "the game on a certain pre-release network",
Metal Gear Solid could in fact be on the way to an XBLA release. If their source is to be believed, the game appearing on PartnerNet is almost a guarantee that it will see release at some point (though sometimes many months later, as was the case with
Ikaruga.) While the Xbox isn't traditionally the home of the series, a port of the second game
did find its way there, so perhaps a port of the first isn't so out of the question after all.