I'm an attorney with connections to government officials in Atlanta, and this is an issue that has reared its head recently. At this point only initial feelers have been sent out from "consultants" loosely connected with Disney (I imagine to maintain deniability). The conversations are not regarding a park, however. The possible development discussed consists of a hotel/resort, coupled with retail space and a few golf courses. The thoughts are plausable from a couple of perspectives. On the hotel end, Atlanta is a destination city, regularly hosting several sporting events (multiple Super Bowls, men's and women's NCAA Final Fours, NASCAR races, NBA and NHL All-Star Races, several PGA tour events). From the retail perspective, Atlanta is the largest city in the South, and anyone who has ever driven through here knows that if traveling through the South, you are probably going through Atlanta. Finally, from the golf course perspective, Atlanta specifically, and Georgia in general is becoming a real golf destination (for example, the Reynolds Plantation courses hosted President Bush as he and the Vice President played golf last year with some of their biggest contributors, and don't forget the Masters in Augusta). The interesting point is that in Georgia, because of very strict Sunshine Laws, negotiations between government officials and prospective businesses must be made public. There is a bill now in the Georgia General Assembly that would change this law, and make those negotiations secret (right now only Georgia and West Virginia have laws requiring such negotiations be made public). The "consultants" I mentioned earlier are big supporters of the bill to make such negotiations secret. Take from that what you will.
Now that I'm done spilling my guts on the information I do have, let me interject my own intuition. This is something that is very far down the pike, and in the EARLIEST stages at this point. Knowing what I know about Disney (my family are annual passholders, and we've been to WDW four times in the last calendar year), from what I've heard and seen, I think this may be a potential DVC location in the future. I know that after the lukewarm response to Hilton Head, there is hesitancy to extend DVC outside of the WDW area, but lukewarm would be a good description of the pace of the events in Georgia now. I'm afraid this may be the property version of Fire Mountain. "The best laid plans of mice and men are oft to go awry."