1. Quality of life in Atlanta is good enough that smart people could be convinced to move here. Its warm, there are good restaurants, there is good shopping, there are funky neighborhoods and bars, its a short drive down to nice beaches where the water is actually warm enough to swim in. Hell, I've been snowboarding 4 weekends so far this season within a few hours of town. It does not have a national reputation for being ultra-hip, but as I said in the other thread, I don't think that matters. In fact, around the turn of the century (am I allowed to say that yet) neighborhoods in SF that were hip and trendy and neighborhoods in SF that were dripping in startup money were mutually exclusive, and being anyway associated with the tech industry was just about the most uncool thing you could possible be there even though everybody was.
2. There are some people who wouldn't move to Atlanta, for reasons that are both reasonable and unreasonable. However, the same thing can be said about San Francisco. Some people will not move there because they don't like the culture or they are worried that they are going to die in an Earthquake. Atlanta does have an undercurrent of racism and that does bare repeating. But its not a death knell for the city as a center for innovation. We have a very diverse community here who can work together and produce great companies.
3. Atlanta has a vibrant, multifaceted nerd scene with various strong universities, technical user groups, cons, parties, mailing lists, web sites, facebook groups, etc. In fact I find it far easier to get networked in with other nerds here than in San Francisco, where scenes tend to be a bit more snobbish, exclusive, and corrupted by the presence of wealth. There are some things I wish were going on here that aren't, such as a genuine hacker space, but in general the "scene" here is strong and growing stronger at a regular pace.
4. In addition to the aforementioned nerd scene, I think the things that matter are the right legal framework for innovation (which I explained in the other thread, and I do not agree that the differences are trivial particularly with regard to intellectual property laws), and a supportive environment of investors and incubators. The later seems to be improving, but unfortunately the stock market crash has made everything more difficult.
5. I strongly agree with jhaynie that Atlanta has got to look at its individual technical strengths. There are certain technical communities that are particularly strong here. Innovation is not about copying San Francisco - its about leading, on the world stage, in terms of the direction we need to take technology. For example, this is a time when every business in world is asking itself how it can reduce its costs. Our concentration of industrial engineers may have new answers to that question that you aren't going to get out of Palo Alto.