"Banking on the possibility"
"Cupertino may be banking on the possibility that after you've heard and become enamored with a Rhapsody song, you'll want to buy a higher-quality version of it from the iTunes store."
I'd wager that you're incorrect - Apple won't be banking on it, they'll have insisted upon it. It's obvious what the two reasons for the bitrate being pegged at 64kbps are:
1) AT&T. They won't want people streaming at 128kbps or more all day every day and they clearly have clout with Cupertino.
2) iTunes. Apple won't let anyone undercut them. So any small company that comes along and tries to do so will be told to Foxtrot Oscar and any large company with some money and some balls, like RealNetworks, will be allowed to play but only on Apple's terms and under Apple's restrictions, of course.