While many of us are still getting acclimated to the recent PS2 release of Gran Turismo 4, and still wondering why they focused so much on the camera modes instead of an actual online mode, Polyphony Digital is hard at work preparing the PSP version of GT4 for a mid-2005 release.
Amusingly enough, GT4 Mobile will have an "online" mode of sorts–multiple players will be able to compete against one another using multiple PSP systems thanks to the unit's WiFi capabilities. It won't take long after the game is released for some enterprising individuals to figure out how to turn that into true Internet play with the implementation of a custom tunneling application and a Bluetooth adapter.
Sony and Polyphony haven't said much about the game, and they tend to keep real quiet about the Gran Turismo series up until a launch, but here is what we currently know:
1) Gran Turismo 4 Mobile will be a port of the PlayStation 2 game. It will include fewer cars and tracks, and the graphics won't be nearly as hot, but as a trade-off, it will include original cars and tracks not found in the PS2 game.
2) The PSP version will push fewer polygons, but Polyphony plans to minimize the graphical impact of that by decreasing the number of generic buildings and other "window dressing" structures in the backgrounds, and by cutting the number of CPU cars down from 6 to 4. This may seem like a bad thing, and in some respects it is, but the upside is that the cars, roads, and structures that do make it into the game will look just like they do on the PS2.
3) The camera mode that Polyphony put so much work into for the PS2 version will also be available in the PSP game. You'll be able to view cars in scenic settings, in a higher resolution than the normal driving mode, shift the camera to any angle you like, and take and store photographs (if you have a memory stick to store them on).
When Sony and Polyphony Digital feed us more info, we'll pass it on.