Hi Kirk,
yes, I know ExifTools, but it would be great if you could just make an EXIF panel that allows me to easily set these values, exactly like your current IPTC panel with the small preview, so I am sure I set the date, etc. for the right image. Ideally you use ExifTools behind (license wise that should be ok) so it should not be a lot of development.
Cheers, Fons.