Sirius XM has released screen shots of its iPhone app for the radio service. The iPhone software will be free, but there will be a $3/month fee to listen to a select group of Sirius XM channels. In other words, for a very modest $36/year, you get Sirius XM on your phone.
Some pundits are pooh-poohing the development, but the iPhone software opens up new possibilities for Sirius XM subscribers without the requirement to buy the specialized hardware. The most likely new subscriber base will come from home-based listeners who want access to Sirius XM in the house but don't want the bother of buying the radio add-ons. If you have an Internet connection, in home WiFi, and some sort of iPod/iPhone stereo (there are hundreds of them), you can drop your iPhone in the base and listen to your favorite Sirius XM channel. This is already being done, using some of the Internet streaming services, but Sirius XM's paid content brings a lot of content you can't get for free.
This gets Sirius XM out of the car and into homes, at a reasonable cost. And it begins to move the company away from dependence on the satellite distribution model, which has always been a limiting factor.