The news that the next chapter in the Metal Gear Solid series is heading to Xbox 360 is certainly extremely good use for the platform, but fans shouldn't be expecting that title to be an Xbox 360 exclusive.
Spong spotted a quote in a recent G4 interview with Microsoft's VP of interactive entertainment John Schappert in which he said of the game you know, we didn't say that it was exclusive”.
You can be sure that if the game were exclusive, Microsoft would be very plainly letting us all know about it. The conclusion – the game is odds on to be heading to PS3 as well. And even Wii.
Nonetheless, at the very least the game will be released on Xbox 360 at the same time as any other platforms – and the possibility of a timed exclusive remains, as do potential DLC deals with either Microsoft or Sony.