The two top tools I've played with are the Music Match and MJ 8. I have about 10,000 songs, and spend a lot of time ensuring that the titles, etc are correct. Pulling matching names is a place that Music Match shines, and an aspect that Music Jukebox could really elaborate on.
More functionality could be done to clean up filenames, such as removing () or {} from the file names. Giving more then a couple fields to try and match to the field name of songs, or even intellignt filename parsing, and cleaning up.
I do like the playlist management in MJ. But it would be nice if I could make 3 or 4 playlists, then create a "master playlist" that uses other playlists as a basis. Now this would be handy for my player, in that I could say I have 20GB of space, and want 2,000 Christmas songs, 3,000 Pop and 4,000 Country songs. (could also be based on MB).
Some of the editng in MJ can be very powerful, but at the same time more batch related tools could be added, to handle larger volumes of songs.
Also the batch related functionality could be added right to the main player view section as a right click feature.
In the Microoft player, you can select a bunch of fields and change them all at once in the player section, not needing to go to a sub screen to do so.
With all the songs out there, or most of them, I am suprised that there is no way to easily extract song information from the internet built into MJ.
Cheers,
Quentin