Hideo Kojima, the famous director of the Metal Gear Solid franchise, tweeted a single image with the following words displayed: "Metal Gear Collection 2014":

The last remastered collection for the series was the Metal Gear Solid HD Collection for PS3, Xbox 360 and PS Vita. What's interesting to note is that it says Metal Gear in the picture and not specifically Metal Gear Solid. I wonder if this hints at a new collection featuring the first Metal Gear title released back in 1987.