Implementation of smart playlists based on moods. Similar to Sony's SensMe channels, playlists are generated based on the mood of tracks. For example, there would be chilled, energetic, upbeat, Slow etc, or time of day.
What are the possible drawbacks or issues with the requested changes?
This would require that the current library is analysed, measuring each track to determine where it lies in the mood spectrum so will need additional entries in the database, and additional file storage too for saving the information. May also add to system resource usage on existing libraries, but otherwise wouldn't expect it to be too much of an impact if it's included in the upload process too.