This script uses the UNIX qlmanage command to display a Quick Look window of the selected track(s), which can be audio, video, and, perhaps most usefully, PDF, whereby Preview.app is not necessary. Also handy for playing a single track out of playlist context. Need I add that a keyboard shortcut makes this very handy.
Caveats: 1) under Leopard a media file will begin playing immediately, so the script uses a hack to prevent this, 2) under Snow Leopard and better the QL window's title contains "[DEBUG]" which cannot be suppressed, and 3) the QL window can only be dismissed by clicking on its close box.
Move selected playlists to a new or existing folder
Use tag data to formulate new file name for selected tracks' files
Change selected tracks' Start Time or Stop Time by user-entered seconds
View/Edit tags of selected track(s) in single window
Deletes the lyrics of every track in the Music playlist
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags