Listening to the Sirius-XM webcast now. XM Chairman Gary Parsons and Sirius CEO Mel Karmazin made presentations and are now answering questions. In the meantime, a couple of slides illustrate their argument about the competitive marketplace. The first one shows the audio entertainment devices around when the sat radio licenses were granted in 1997 and now, a decade later:

And this one shows the difference in audio audiences or potential audiences; Sirius and XM combined are in blue:

The slide presentation is in this pdf