implement smart playlists in addition to stations
It would be great with support to create "smart" playlists. I.e. playlists that are automatically updated based on filter rules. All ID3-tags and other metadata like last played, date added, play count etc. should preferably be available for filtering.
See iTunes for inspiration which has good smart playlist support (but don't support FLAC and online services...)
Advanced filtering incl. logical operators AND, OR, NOT in combination with compare operators like IS, LIKE, CONTAINS, STARTS WITH, ENDS WITH, BETWEEN, AT LEAST, AT MOST, ...
Make it possible to limit the objects in the smart playlist based on number of items or playtime. Allow user to select priority criteria to select kept items, i.e. random, most played, least played, recently played, recently added, highest score etc.
Allow an option to make the smart playlist dynamic or not, i.e. automatically fill based on filter criteria each time used or only when created. For static smart playlists a manual update option would be nice.
This would be a huge improvement for users with large locally stored collections.
Possibly the Station functionality could be improved upon to provide the wished for feature if more metadata becomes selectable, not at least the Origin source.
For online services the "Station" support is possibly the only way to do it efficiently if the online provider does not support filtered queries on such metadata.