This is kind of recent news - Delta has been apparently having some tough times, and is therefore doing all sorts of things to attract customers (coincidentally, as someone mentioned before, Delta is based in Atlanta) As of today, they began slashing prices, and there are some great deals. There was some information about how late you can book to get the deals, but i can't remember the exact dates. Here's a website if you'd like to see for yourself. It might also be a good idea to sign up for their e-mail programs so you would be able to find out any specials right away
http://www.delta.com/home/citypages/...ares/index.jsp