Rafat Ali, on PaidContent, points out that the new iPhone app to listen to public radio could be a game changer, transforming the model of local public radio listening to a more national, a la carte one. There's also some back and forth about whether the app -- which will eventually allow contributions from the phone, and may be available on other phones, too -- will hurt radio stations by removing local loyalties, or help by encouraging more contributions.
I see another issue: will the new app cause a split in the public radio audience, between the have-mores and have-lesses? As I wrote in a comment:
Those who use smartphones will tend to be of a higher socioeconomic status, and probably be younger, than those who listen only over the air. Phone listeners will get a richer, more diverse set of programming, and at some point may be more highly valued than those who listen only over the air. It’s analogous to cable vs. broadcast, and how the broadcast-only audience is less valued, commercially, per viewer.
Public radio may find some dissonance between its mission to serve all and its desire to target higher revenues. The public radio listener demo tends to be a higher educated and desirable economic group than radio listeners overall, but what happens if that public radio group gets split into the have mores and the have-lesses?