A second hotel is available to book: Kimpton Overland Hotel for $149/night. Looks like a great property and a fairly new one at that.
Some preliminary tour details are also out. They have plans for ramp tours at ATL, tours of Delta TechOps and their training center, visits to the Museum of Aviation at Warner Robins AFB in Macon, GA (about 90 minutes south of ATL) and the Commemorative Air Force Airbase Georgia in Peachtree City, GA (about 45 minutes SW of ATL), guided tour of the DC-3 inside Delta Flight Museum, and access to the 737-200 simulator. Hopefully more to come.