It has indeed been a very long wait and unfortunately, there's no knowing when the game will finally hit store shelves.
But at least the game's director has apologized. During a recent Edge interview , ICO and Shadow of the Colossus guru Fumito Ueda apologized for the numerous delays suffered by The Last Guardian .
"More than anything, I feel terribly sorry that for various reasons I have kept my audience waiting for such a long time."
The game has been in development for over five years now, even though Ueda's contribution to the project was apparently completed "a long time ago." Unfortunately, he can't give us a status update, either, as he says the "details of when, where and how" the game will be finished are beyond his control. Well, remember that he left Sony some time ago, and he has been performing his services on an outside contractor basis.
Over the years, the updates have not been encouraging. We've heard reports that Ueda isn't exactly the easiest guy to work with, and Sony boss Shuhei Yoshida has said that development is "very slow." At this point, it's probably safe to assume that Guardian is a PlayStation 4 project; let's hope we hear more soon.
Related Game(s): The Last Guardian