Sure, it could be that Harrison let slip the near-complete condition of a presupposed PSP sequel, but he's got more business savvy than that. Besides, IGN was asking him what he'd been playing on other platforms, ruling out PSP and PS3; not that more LocoRoco isn't headed to those formats. In December, Harrison confirmed that multiple LocoRoco games were in development, indicating that a PSP sequel is likely underway. That some of those cuddly blobs will be bounding onto the PS3 store seems like a no-brainer too.
[Via PSP Fanboy]