How about
- A ‘remove this song from playlist’ button in the play screen.
- Allowing us to save and restore playlists by downloading/uploading them
- An option to start playing at startup. Now I need to log in and press play after a power failure.
- Adding support for multiple playlists
- Adding support for streaming the audio through the web interface. More as a pre-listening option when building or editing playlists.
- Adding support to check for a new version and doing an online update.
Those are the first things I missed after playing with Volumio for just a day 
Great piece of software, I look forward to the next release ! (hopefully with some of the features I suggested, included 