You might checkout:

http://www.mp3machine.com/win/PLAYLIST_MANAGERS/

and this entry in particular:

http://www.mp3machine.com/software/Helium/

Also http://showcase.netins.net/web/phdss/mp3/mp3_playlist_editors.htm

I don't know much about them, since I use my own program (CSDS) to organize mp3 files. Screen shot from CSDS