On itunes:
Iirc, 99p for a track can upgrade for 20p from the normal tracks.
256kbps unprotected AAC format <--- fine quality for portable audio players, I rip at 320 but that's really just 'cos i can..
Only EMI's library is DRM-free at the moment, Pink Floyd are the band i remember definitely being on there but i'm pretty sure there's thousands and thousands of tracks available.
To access i believe you get asked to configure it in itunes and you can choose to buy normal Fairplay-ed tracks or the higher quality DRM free tracks.
Haven't heard about other major DRM free moves.
You know about emusic.com i assume, they offer mp3 downloads free from DRM, but of course aren't supported as well by big labels. Also offer a subscription based model with a quota of tracks per month and 50 free mp3s when you join, no obligation - very good site.