For what it’s worth, any independent musician can get on iTMS if they sell their music through CDBaby. They charge something like a $30 one-time ripping/encoding fee, and then give the musicians a pretty sizable chunk of the 60% cut which CDBaby gets.
Though that’s not really a useful option for me, since I make all of my music freely-downloadable (for anyone who’s smart enough to figure the URLs out, anyway) and basically just offer the physical CD as an artifact for people who like that sort of thing.