I also think the $89.00 one way fare is really good. I just read that airfares will continue to rise in the coming months as fuel costs are again going up.
AirTran does, on occasion, post $49.00 fares but there does not seem to be any pattern to when they do this. Also, I have seen when then do this that sometimes you can get one way for $49.00 but the other side of your trip can be something like $129.00. If this happens you will gain nothing. You need to visit their web site every day and several times a day. If I were you I would grab the $89.00 and forget about it. If fares go up as predicted and you wait for a special that doesn't happen you will really be stuck. On the other hand, if they go down or AirTran does run a special you will still have reservations with a good price.