Originally planned for release in Japan during Spring 2005, it seems that Gran Turismo 4: Mobile Edition continues to follow its home console predecessors in falling behind schedule.
Speaking to Japanese publication Famitsu, developers Polyphony Digital have confirmed that the game has been given an indefinite release date. The news is the latest in a number of blows to hit the PSP, following the decision by several movie companies to stop producing UMD Videos for the handheld, and recent suggestions that Sony's platform is on death's door.
Gran Turismo 4 on PlayStation2 was released in 2005 after slipping from an original release date in 2003, so with that in mind perhaps we shouldn't expect the Mobile Edition to hit retail until well into 2007...if at all.