Voter turnout was up in GA over 2004. 62.7% vs 56.4% of eligible voters in 2008 vs 2004 respectively. In actual numbers of voters it was an increase of 19%, 3.94 million vs 3.32 million. http://elections.gmu.edu/voter_turnout.htm.
However, my thought for the longer lines at some polling places was because of changes in where many were told to vote and the number of polling locations available. That being said there are many, many reasons why it takes longer at some polling stations than others no matter what the turnout, so guessing at the reasons is futile. http://www.hartic.com/files/LongLinesWhitePaper.pdf
I have voted in every election since I was able to. Five in GA and in two of those the lines were long, 1996 and 2004, and took about two hours. In 2008, I went back to the same polling location in 2000, and I was in and out in less than 40 minutes. In any case, very few people talked to each other about the election and if they did it was not about who or why they were voting, at least in the groups around me. I say groups because the lines snaked back and forth and you ended up next to different people as you moved forward.
Some interesting reading about voting and voter fraud