I have just committed revision #21207 which includes playlist export. Playlists can now be exported to M3U (*.m3u), Extended M3U(*.m3u) and Shoutcast Playlist (*.pls) formats. You are also able to select whether to only export Music Files, Music and Video Files, or All Files (Full Backup).
I have tested it on every linux media player I could get my hands on that supports media on network shares, with positive results. I would be interested in hearing how the generated playlists do on Windows and Mac platforms.
If anyone is willing to do some testing, here are the instructions to get it working...
1) Have a development environment installed
2) run an svn update on the charon-merge branch (should get you to svn revision 21207 or higher)
3) Copy the following files from ~/charon-merge/web/pluto-admin/ to /var/www/pluto-admin/:
Export options are available from the main playlist page, and the edit playlist page.
Once I can confirm that generated playlist work as expected in most cases, I will finish the playlist import functionality. Of course, if you notice any bugs or anything out of place, please post here so I can fix it.