For those of you who live in the cool part of Atlanta, you have the PATH. The main part of the trail runs from near the Carter Center south of Ponce on its own paved trail (with sections on roads). I’ve only run a small part, but it goes all the way to Stone Mountain. That would be quite a run (17 miles, according to the website), and if you could get someone to pick you up at the end it would be a good way to do a long run.
I haven’t run the Silver Comet yet. I generally am wary of running on rail trails since there are so many cyclists and rollerbladers, but runners have just as much of a right to be there as anyone else.
On a larger note, I think it’s great that the Atlanta area is making places like this now, because before too many more years go by the growth and development will make it very difficult. There aren’t many cities in America right now that have the kind of resources and space that Atlanta has right now, and it’s important that the town takes advantage of it soon. Those who oppose projects like the Beltline should recognize the fact that the window of opportunity for projects like these will close before too many more years go by. A lack of foresight today will harm Atlanta’s ability to maintain its increase in national status in the future. Sorry for preaching, I’m done.