Counting nine trailers since the original at Tokyo Game Show 2005, Kojima Productions assistant producer Ryan Payton has told MTV Games' Stephen Totilo that their latest video, from this year's TGS (see video below), "could be the last trailer [for the game]."
"The pressure is really on to finish work on the game, and we have decided not to be sidetracked by any more promotional work," he said. That doesn't rule out making more cinema once the game is completed, but don't expect that anytime soon.