It seems we were right to doubt him too. Snake may be gone, but Raiden lives, and while there is a subprotagonist, there are always sequels to be made. Cue: Kojima's "Mission: The Next MGS" and a tiny picture of Raiden in the corner.
Announcement will be made at E3. We're most curious about what platform Kojima will release the game on. We can't help but think if he decides to put the game out on XBOX 360 or Wii, it'll be a step down due to technical limitations.