SlorgNet on 15 February 2008
Ryan Payton at KojiPro has said there are no current plans for a demo. However, that said... they're still in the middle of polishing the game (and you know how Kojima polishes his games - down to the last nanometer). I'm sure the design team would love to release a demo, but they're in crunch mode and just don't have the time right now.
I do hope they release a demo shortly before the April/May/June release of the game, though. MGS4 is going to be a landmark of the world media culture, and a demo would be a terrific way to spread the word.
