o I think it would be reasonable to request at least a way of displaying Facetags from Windows live Photogallery and Picasa. Both these applications now save the facetag rectangle in the image. Additionally, populating the People tag based on the facetags would be a nice feature.
o 1 to 1 mapping of city-state-country exif tags with MC tags, of course... In general, a Complete EXIF and IPTC one to one relationship with MC tags.
o Another feature which I'd think many users would like is simultaneous geo location (map) and image. Picasa does this. Picasa also geotags images but I don't think JRiver should implement functionality to geotag pictures.
I don't believe Face Detection and Recognition should be a part of MC. Those are difficult and expensive techologies which require large development and support efforts. So these functions are much better taken care of by other companies such as Microsoft (live photo gallery), Google (Picasa), etc. Thus I believe a "trade off" wrt. face tag data would be to support displaying emerging standards such as Microsoft Photo 1.2 XMP and Picasa's new tagging format.
With regards to exif and IPTC: MC would benefit in wrt. user base if it supported various versions of IPTC with the same vigour as Audio IDvxyz is supported. And, why not expose all EXIF, IPTC, and XMP tags to the user as "raw data"? Then we could derive tags using the regex engine?