Reference:
http://getmusicbee.com/forum/index.php?topic=15404.0Clearly the functionality is there (Show Artwork) so I don't think it'd be a huge issue to implement the code for it to show up in the library. Would be really appreciated because MusicBee is so good, I use it for Audiobooks and Videos as well, it's really amazing to keep it everything so well organized and covers would make it even more amazing.