It's a blink-and-you-miss-it tease, but it looks like Metal Gear Rising 2 may be in development for PlayStation 4.
Appearing during part of Taipei Game Show's live stream (not to be confused with Tokyo Game Show, which shares the same acronym), the image you see above flashed quickly during a montage of upcoming PlayStation games. During an The Order: 1886 clip where the team is counting down for a payload drop, during the number two, a number two with the Metal Gear Rising font flashed on screen.
Thanks to Aaron Quixote for the news tip!
This certainly feels like a Hideo Kojima-flavored tease. I can't think of much else it could possible be. Maybe we will find out more at E3.