Goemon has already achieved at least half of this.
With his t4roku it’s possible to rate songs via the remote.
Unfortunately the ratings are only stored in the database and not written to the files.
I’m sure this will somehow be possible to manage.
On a sidenote, I’ve found Songbird to have the ability to write ratings into the files itself.
There is some hacking required to enable this feature, and the ratings aren’t compatible with the 0-255 ratings that firefly reads. Still it’s a start.
Other than that there is no solution that I know – I’ve been tinkering with this problem for quite some time, too 😉