New fact sheet
* Support for 1-4 local players (split screen) and 16 online
* There is, of course, a damage model now, with the race cars featuring accurate performance and body damage based on point of impact and velocity (though, I would suspect all the cars will have performance-altering damage as well)
* Cars accumulate dirt, tires smoke, and bodies spark on roll-overs (so yes, the cars also roll over)
* Physics engine is brand new and will replace the Prologue engine
* Head tracking with PlayStation Eye to allow for looking around the cockpit, etc.
* More than 1000 licensed cars, including those from NASCAR to WRC to Super GT
* More than 20 tracks with 70 variations
* Gran Turismo TV has both SD and HD broadcast-quality video, and the video can also be exported to the GT PSP Museum
* Photo Album shots can be uploaded online to share, as well as replays from the Replay Album, which will be uploaded to YouTube
* Support for custom soundtracks
* Races can support up to 16 players online, but you can also create private lobbies, which can hold up to 32 racers
* Text and voice chat is supported, but be careful texting while driving

* Cars unlocked in GT PSP and GT5: Prologue will also be unlocked in your garage on GT5 for use in Arcade Mode