They haven't made any confirmations on what systems it'll be available for, but an IGN article states that it's likely that it'll be on a Sony system (or systems, if it comes to the Vita). It's still a long ways out, but I'm pretty stoked an old-school styled RPG like Rainbow Moon would get a sequel.

The details are still pretty sparse right now, but there was mention of capturing monsters, new dungeon assets, and a new setting with a parallel light/dark theme.

I assume after Rainbow Skies is Rainbow Fog, shortly followed by Rainbow Grass, correct?

@video_game_king: With a spin-off somewhere in between called Rainbow Rainbows, which will be a leprechaun sim racer.

@sparky_buzzsaw:

It's gonna be an expansion pack for Rainbow Fog.