Speaking at the developers community event in LA yesterday, community manager James Stevenson revealed that the developer would "support Sony" in developing any games for the platform, but would "probably not" develop any portable games in house. In other words, you can totally expect a Ratchet & Clank game on NGP — just not from Insomniac.
We already know a Resistance title is in development for Sony's new portable system. That's being handled by PlayStation Move Heroes developer, Nihilistic. It's a bit disappointing that Insomniac don't want to get involved, but we guess it makes complete sense.