Split screen is PS3 only.
Sweeeeeeeeet nectar
http://n4g.com/ClickOut.aspx?ObjID=131794
Heres a link. It was an unfinished review, but oh well. Its about as reliable as this article was. PS3 has better frame rate less pop-out, most cars/people on screen, and allows split screen. It is also less cartoony.
While I dont think we should trust any of this until we get a review from a trusted site, I wanna post this to see Rock on deny validity of this while supporting sarcastic gamer. Lol.