It would be nice to extract tags from the playlist name. For example, if I have a playlist to sing for each day of the week, I would like to tag them all with the tag “singing” automatically. So I could just call the playlist with a pre-defined structure (“Singing/Friday” or "#Singing# Friday for example) on the server and then Symfonium could detect the tag.
The only problem with tags is that, if a user has several devices, there is not a way to sync tags. This is specially a problem when you have several playlists of a specific subject, and you want to keep them grouped on several devices.