The Obligatory XM/Sirius Merger Post
I don't see any of this as a significant threat to public radio. For the most part, our listeners don't consume media by the pound. They tend to be selective. XM's positioning statement "Everything All the Time" probably has little appeal to the bulk of public radio listeners. In a merged market, "More of Everything All the Time" isn't likely to change that.
The satellite radio business model, selling new radios and charging a subscription for each one, is a barrier to subscribing. A lot of public radio listeners won't go through that barrier just to get the few content options that are truly appealing.
The real threat, in my opinion, is when a single subscription to XM/Sirius will allow you to log on and listen through any Internet-connected device in your home, car, or office. The wireless web will unleash the true marketing power of the satellite content, particularly if listeners can select lower-cost packages to get just the programming they want.
Instead of "Everything All the Time" listeners will get "What I Want, Where I Want It." That day is still down the road apiece, but it will come. Public radio should start preparing for it now.