Also, I know the Senate and Governor's races are the big draws for everyone's interest in Georgia this year, but every other statewide race (and there are several) have been very close in polling as well. All of those races only have a Democrat and a Republican, so they'll all be decided on Nov. 4. Depending on turnout and ticket-splitting there's a good chance of a few upsets on election night.
Like I said above, the School Superintendent race is the big one to watch - all polling there has been tied for week, and the incumbent Republican's endorsement of the Democrat is likely to make some impact at least.
Also something I've wondered about is if Nunn does relatively well among white voters, would that help any Democrats not named John Barrow in south Georgia congressional races?