IGN seems to think Phil Harrison accidentally announced LocoRoco 2. Their proof? Let me quote their article, "When asked what he has been playing on other platforms, Harrison said he has enough to play on the PS3 and PSP. But he said he was playing 'LocoRoco's next version on the way' to the Q&A. Harrison didn't provide details, but the fact that he was playing the game on the go would mean it will arrive on the PSP."
I suppose that's one way to interpret it, but I personally think he was talking about the LocoRoco Mobile, that has already been announced. After all, the question that brought on the LocoRoco answer was about other platforms, ie not PSP or PS3. It also seems unlikely he'd mention a high profile sequel in passing. We're sure LocoRoco 2 is in the works since they want to continue the franchise, but we're still waiting for the official announcement of another PSP go around. Let's hope that it comes soon!