Small feature: a menu item that allows the user to manually check for an update—probably under Help, next to the About option. It might also be good to place an equivalent button (or an indicator of whether the user is running the latest version) on the About MusicBee window itself, if the user is viewing that.
Certain users (or perhaps just myself) rarely restart their computers and thus have MusicBee running for long periods of time, and this means that update checks are few and far between. Having the manual option is useful to avoid restarting the computer manually.
(This also raises the possibility of polling for updates on a daily/weekly basis, but that's just icing on the cake if present.)