LET THE SPECULATION COMMENCE. Tweeted today by Hideo Kojima himself,  the screenshot above is said to be from Kojima Production’s latest Fox Engine title. Couple this with the recent announcement that MGS5 is indeed in production, and let the wild speculation begin.
If the above image does in fact contain Big Boss, then consider this merely an image of a tank. Keep in mind that this comes on the heels of two other images of FoxEngine demonstrations seen below.