I noticed this myself the other day and it has been mentioned on FlyerTalk. AirTran is now charging a premium to preselect rows 12 though 15 of coach. $13 fee now gets you those seats, they also board in zone 1 when in the past these were usually zone 5 or 6. Still no charge if you go through Kayak. If you have already selected seats you can go in and change them to move further forward on the aircraft.