That and more is revealed as part of the latest update on the game's progress from Bill. Sound like they're wrapping up on the first episode.
I have confused feelings about this, since I was rather hoping Pedro would be invited back to do the new music, in keeping with tradition. But who the hell can complain about Jared doing the soundtrack to anything? Sounds like some of Pedro's music from Ghost Pirates - which Duke Grabowski is technically a spinoff of - will be reprised to complement Jared's original work.