@robsamuel: Agreed, very much doubt they will put any effort into porting psp games regardless of this games success.
If they gauge interest to be high enough a new game would make more sense, and personally be more interesting, than a handheld port.
Never say never. SEGA is weirdly committed to this - the port was made internally rather than being farmed out to a third party. Also, porting a PSP game is most likely quicker (and cheaper) than creating an entire new game from scratch.