http://www.cnn.com/video/player/play...r.business.cnn
According to the above review [warning: video], the "social" is that if you ever find someone else with a Zune, you can share a song with them, and they can listen to it up to three times, before it will no longer play and they are forced to buy it. The Zunes will sync up to copy the file and its DRM.