Craig isn't a ghost town at all. Selma made use of all the housing on base, and many business/agencies use other base buildings. Beechcraft had a C-12 facility there back in the 80s but that's gone now. A couple of business built plants on one of the runways. So all in all, Selma has made great use of the former base.
As for Robins, the largest unit there is the Warner Robins Air Logistics Center, providing depot maintenance, engineering support and software development to major weapon systems (F-15, C-5, C-130, C-17 and SOF aircraft). The 5th Combat Comm Group is there, and the 461st Air Control Wing (ACW), Air Force's only Active Duty E-8C Joint Surveillance Target Attack Radar System (STARS) wing. When the B-1s were there it was a Georgia ANG unit, and then the USAF took the B-1s back to active duty. A few other unit there as well, not to mention the Museum of Aviation, a great museum and 2nd largest in the Air Force. Link below:
http://www.museumofaviation.org/