During the Metal Gear Solid 25th anniversary announcement today, Hideo Kojima announced Metal Gear Solid: Ground Zeroes (yes, that’s ‘Zeroes’).
According to Japanese gaming magazine, Famitsu (translated by Andriasang), the game will be taking place an in open world setting using Kojima Productions brand new Fox Engine and will be available on the Playstation 3 and Xbox 360. There has been no time table for release. Additionally, there was also no mention on when this game will take place in the Metal Gear Solid timeline.
It was also revealed that a movie project was also announced during this event. The movie will be spearheaded by producer Avi Arad and will be released by Columbia Pictures.
Here is a piece of artwork that was also released with the news. This may give a clue on when the game will take place: