Breaking with the rest of the music biz, Sony BMG is partnering with Grokster for a sorta kinda P2P venture:

Although many of the details are still in flux, people familiar with Mashboxx said that it would probably work like this: When users search for a Sony BMG track, the system will allow them to download only authorized versions of the song.

In some cases, these could be free promotional tracks that come with an offer to buy higher-quality renditions of the music. Mashboxx hasn't set any prices. Many online music stores sell songs for 99 cents each.

The idea behind the venture is to let people continue to use file sharing to discover music at no charge, while encouraging them to pay for the songs they want to keep.