I've been assuming a client-server model, so that you could play versus a pandora in the same room just as well as one across the planet.
Unless the pandora reaches DS type production levels, or there's a Pandora owners convention, I'm not seeing much point in developing anything peer-peer.
It *might* be nifty to develop a cross platform app that could connect to a DS. I might be interested in that. That might theoretically springboard to Pandora-Pandora connectivity.
Client-server would create so much unnecessary lag for people who ARE in the same room, not to mention you would need to have net access to do it.