On-demand satellite radio it isn’t, but the kind of service outlined by Sirius’s Mel Karmazin before a House committee recently is a step in that direction.

The kind of packages he was talking about were of the tier variety, where you can subscribe to a group of music stations or a group of talk stations or even a group of sports stations. Subscribing to just that tier would naturally cost you less than getting the gamut of stations that you can get now for US$12.95 a month.

We’ll know more once the merger with XM gets back out of antitrust limbo.