Microsoft Zune Announced

After months of buzz, Zune was officially announced today. Lots of mixed review, as could be expected. The most interesting coverage I found was Engadget's interview with J. Allard. It wasn't until reading that interview that the WiFi and music sharing functionality started to click for me. I'm a bit of a music freak, and love sharing recommendations with people. The 3 Plays or 3 Days bit is brilliant. My question, is when the song is deleted, does it leave a trace behind? I'd love if it remembered what song it was, so I could go and buy it. I need to read more about the Zune store before I consider buying anything though. I'm picky about sound quality and DRM... If it is all play-for-sure... I'm just not interested.