To my ears, it sounds like they are aimed at enlarging the under-100 IQ set.
I went to XM originally for the jazz and classical because even though I can get 3 PBS and Temple Jazz (WRTI, it's a real good jazz/classical public station from Temple U. in Philly) I got tired of the liberal NPR news bias and EVEN some of the jazz DJ's late at night piled on Bush. I don't need that crap especially when they want my coin to survive. Anyway the concerts, XM just did Bonnaroo and Telluride and some of the other stations like Frank's Place and On the Rocks just cinched it.
I'm a bit of an audiophile within my budget and even though XM sound isn't quite CD quality but maybe equal to good FM I actually find myself listening to the music again rather than worrying if the system sounds right and what tweaks I can apply when playing expensive SACD's and DVD-A's.