At the Metal Gear 25 year anniversary event in Tokyo, Hideo Kojima unveiled a demo called Metal Gear Solid: Ground Zeroes - turns out it is being made into an open world game and it was running on a high-end PC at the event. It was also confirmed that Kojima Productions were working on next gen hardware - so it's safe to assume this game won't be an exclusive PC title.
The game was running on the Konami's new game engine - Fox Engine - and in the brief demo Snake was crawling, avoiding spotlights, driving, killing guards, and piloting a helicopter all the tune of Ride of the Valkyries.
The first piece of artwork from the new game can be seen below.