From EU PS Blog, " Hi everyone. My name's Liam and I am the European Product Manager for ModNation Racers! So another week has gone passed and I'm ready to announce some really exciting news.
ModNation is going Portable!
Yep that's right PSP owners will be able to get their hands on a PSP version of the game; allowing you the same creative tools to make your mod, kart and tracks while your on the move/on holiday/at your grandparents house. You will also be able to upload, download, remix and race creations by the PSP ModNation community."