Boston’s Howie Carr is local and conservative and does well.
Podcasting is replacing the AM for younger people. Also podcasting is slicing things up into smaller and more targeted areas of interest, rather than “general” talk shows.
There are whole podcasting networks devoted to just Technology or even mostly just APPLE tech. ESPNradio is jumping whole hog into podcasting.
What form it will finally take will be interesting, but the “airwaves” of TV and Radio will probably eventually be used for something else.