At the moment I'm using it to process a few hundred gigs of song files that I've collected as a big furry hairball of a mess over the years - something about having multiple iPods and MP3 players over the years, and not really doing very good house-keeping in the move from one to the other (and avoiding things like iTunes where possible) has meant that I have a lot of files that may have duplicate songs in them - but the filenames and organization doesn't necessarily reflect that fact.
So I'm using dejavu right now to clean this up .. I'm assuming you'd be happy to have a "find_duplicates.py" script added - if so, I'll let you know as soon as I have one working .. ;)
Thanks again!