I bought my Oct. 25-Nov. 1 BMI (Bloomington, IL) to Orlando ticket when the sale fares were $94 (+ taxes) each way. The Nov. 1 airfare went down to $80 this week, so I got a $14 credit. (Other flights on Oct. 25 were also $80, but not my non-stop flight.) I'm waiting to buy my December ticket until they have a sale that includes December dates.
I would NOT expect to see September or October AirTran fares go down further than they were this week!