I don't know about most people, but with this kind of delay, I end losing interest in buying the game, even if I originally highly desired the game. It was the same with Tekken 6. I was originally anticipating the game. They even finished the game (had it out on PS3 based arcade machines). At the last minute before releasing on the PS3, they decided to 're-work' the game and make a port for Xbox 360, and delay the release for more than a year in the process. As a result, I lost interest. The same goes for GT5. At this point, I may buy the games when they go to 'Great Hits' status, then buy used in a local pawn shop for $9 or $10.
-Chris