Reverse geocoding means AFAIK putting location data as place, state and country in the IPTC.
I'm trying to imagine the enormous database it would require to add place, state and country based upon map coordinates. It depends upon how local you want place information I guess. State and country might be manageable, but place would require huge amounts of data. Maybe my definition of "place" is different than yours. Place for me is "My house" or "My neighbors house" and they are fractions of a minute apart geographically. What software are you using now that has such a database?
As far as displaying a map for images that have geocoding as szurkebarat mentions, Photo Mechanic already does that. Just right click on an image and select Show Map and PM displays the location of the image.