Atlanta's not "there" in terms of the urban vibrancy that makes a city different from a conglomeration of suburbs with a bunch of tall buildings in the middle. In my opinion, that's what separates Atlanta from the A-list cities in this country -- NYC, Chicago, yes, Boston, San Francisco, even L.A., etc. In terms of numbers it is certainly there, with the exception of one: center-city population density.
Atlanta: 416,474 people; 3,161 per square mile.
New York: 8,008,278 people; 26,402 per square mile.
Chicago: 2,896,016 people; 12,750 per square mile.
Boston: 589,141 people; 12,165 per square mile.
San Francisco: 776,733 people; 16,634 per square mile.
Los Angeles: 3,694,820 people; 7,876 per square mile.
You can make an argument that density is not the all-important measure many perceive it to be. That's fine, but 3,000/square mile is not remotely near the critical mass necessary to consider most of the city "urban." The suburban town where I live 25 miles from Boston is denser. The unfortunate fact is that tall, impressive buildings on desolate streets do not a great city make.
It looks like Atlanta's moving in the right direction, though, as these projects alone could add 10,000 people to the city in high-density developments. I lived there for eight years and was continually frustrated by how the great existing neighborhoods were afloat in a sea of sprawl. I'm optimistic that intown Atlanta can become truly urban. Hopefully, the big-city street level retail and pedestrian activity and diversity will follow.