Clinton has a better chance of winning Georgia than Republicans have of winning Pennsylvania. Four years is a long time demographically when it comes to elections, Clinton would probably win Georgia if she ran, because of shifts in the Metro area and performing better than Obama in ancestral Democratic areas.
With all things being equal I'd put Georgia at about 55-45. She would have to have Obama 2008 numbers to have a chance at winning. Making it close could happen if she's willing to spend time and money there as opposed to Virginia, Florida, Ohio, Nevada, and Colorado.
Predictions should not be based on what you want to happen. The fact that Hillary could do better in ancestral Democratic areas and because there are trends in the Metro area, it's highly unlike that she'd do worse than Obama. Even if she doesn't do better in ancestral areas, she still should perform as well as Obama in the Metro area.