I think it would be cool for Netflix to have music subscriptions also. I think a few choices like free listen only with a few commercials for subscribers of disk and/or watch instantly, paid listen only with fewer commercials, paid listen only with no commercials, and paid listen and download. and buy songs or albums.
Pandora charges $36 a year so a choice like that would be cool, i'll even be willing to suffer a few commercials and even an interactive commercial or short servey to help keep "My" subscription cost down but only at the beginning of a session.