I too am contemplating doing this. I have a question about video files that use the .id3 sidecar files:
Does anyone know if _all_ attributes for video files are indeed stored in the .id3 files?
I was poking around one of my .id3 files with taglib and found title, an image, and some other attributes, but couldn't find the "Media Sub-type" and "File Format" fields.
Alex