I have a Zune. I don't like the Zune software. I use Winamp to play all my music on my system. I created some playlists for my Zune that I wanted to also listen to in Winamp. I didn't want to convert the playlist through Windows media player or perform any of the other cheesey hacks that are commonly used to convert the files. So I bring you... Zune Playlist Converter. Another original application by HazteK Software. For more information and a download, you can visit the information page, or you can download the application directly via this link: ZPL2M3U.zip. Zune Playlist Converter can convert a ZPL file into either a M3U file or PLS file, both of which are compatible with Winamp, along with many other players.

And here is a screenshot:

Note: This application has been updated since this original post. It originally could only create m3u playlists, but can now create pls files as well. The new version is 1.0.0.2.