If you remember, last year, in response to legal motions by the RIAA, iMesh cut a deal and began work upon a "legal' p2p system.  Supposedly making use of AudibleMagic's audiofingerprinting tech for a filter, iMesh is rumored to be working on a system that filters out those files not approved for sharing.  The remaining files will probably be tracks for sale, or promotional tracks carrying some type of DRM.  The firm has been allowed to continue the functioning of its classic p2p application, with the RIAA's approval, while working on the new version.

At the same time, Mashboxx, in partnership with Snocap and Peppercoin, is working on their pay through P2P platform.  Release dates uncertain.

I wonder how popular these filtered p2p applications will really be.  What will make them diffrerent from downloadable music stores, other than the odd chance you might find a file that has made it through the filter.  Also… the RIAA probably wants this thing to launch prior to the Supreme Court case, as proof of concept on the filtering front.  We shall see.