It was planned for the roof to be closed for the kickoff games, so doesn't matter if they have it operational or not. Falcons don't plan to have it opened until at least week 3.
The interior is complete, the field was laid a couple weeks ago.
And as was mentioned, they're already tearing up the Ga Dome.
Already have my tickets for the GT/UT game, as they included them with our season tickets this year, and will make for a great end to DragonCon that weekend.
I feel sorry for anyone looking for parking during the FSU/Alabama game, as DragonCon will be in full swing that day, with the parade being the morning of the Bama/Noles game. At least our game is during the last day when most will have left around lunchtime.