Metal Gear Solid V: Ground Zeroes

Metal Gear Solid: Ground Zeroes is an upcoming game in the Metal Gear series, announced during the Metal Gear 25th Anniversary.

Plot
The overall plot has not been revealed yet, but there was some bits revealed:

At some point in the game, a man in a business suit arrives at an undisclosed location to give a boy in a cage a portable music player, with the background music later playing Here's to You from Sacco e Vanzetti. The mysterious man then proceeds to leave as well as remove the logo "XOF" from his helicopter, although he then mentions very vaguely about the events that transpired, as well as removing his hat to unveil a burned, bald head with scars. He then throws away an entire stash of "XOF" emblems, before a spy emerges in the base, with the tagline "From FOX, two phantoms were born." Afterwards, the spy removes his visor and reveals himself to be Big Boss.

Comments from the demo also hint that the crawling mechanic returns after its absence in Peace Walker. In addition, it also alludes to Big Boss driving a jeep and calling an evacuation via helicopter.

In addition, the story hints also mention Paz and Mother Base, although whether they are just lead-in references from Peace Walker or if they'll actually appear in the game, and in the former's case, whether her survival will be revealed or not, have not been determined.