I'm in the NE Atlanta suburbs as well and I've struggled with the same thing (connecting with like minded individuals) after moving back to Atlanta from Washington state after college. I've sort of resigned myself to going it solo. But, I have some resource that might help.
You could troll your work for someone who's interested in hiking but never had the opportunity. I've found a few people in the gym I work at this way, just haven't pulled anything together. I think REI might have trips where you could meet people as well.
There's a Backpacking Light S. Appalachians Club on Facebook which you can find here: http://www.facebook.com/group.php?gid=228683055956 although it's relatively location specific they seem to be pulling together more trips.
There's always this: http://www.atlantaoutdoorclub.com/. My mother foisted the idea on me as a way to meet single outdoorsy women, I never checked it out (although it is free) no reason you couldn't use it to do the same thing! I need to take a look at this again, actually.
As we are of roughly the same age, location and interests if I can offer any help feel free to PM me.
Edit: Trevor had the exact same idea I had.