It may be called "I Love Katamari," but it's not a knock-off. Straight from Namco Bandai, you can start rolling it up with your iPhone (or iPod Touch's) accelerometer for US$7.99.
I Love Katamari takes up 82 MB and features four gameplay modes — Story, Time Attack, Exact Size and Eternal. Only three reviews up so far, one complains about the frame rate, but that seems a problem of the iPhone and not the application itself.
Anyway, it's Katamari on your mobile. Had no idea this one was in the works.
I Love Katamari [Link opens iTunes. thanks Veselov, Falsoman and others]