If you are planning on buying JetBlue or SouthWest when the fares first come out, then maybe you'll get one of the cheap seats. As far as I know, the only way you're gonna get the cheap seats for prime times on the legacy carriers is buying at the 331 day mark. Tho I managed to score cheap direct tix for our February dates, the folks who tried last night were not as lucky, even tho they used the same strategy (not sure about the friend I advised tho, I am hoping they got something good).
It seems to me that the flights for prime periods, like spring break, Xmas and Thxgiving are like the family silver at the garage sale: even if they are for sale, they are not gonna let them go cheaply. These are seats that they are almost guaranteed to sell (just try to find a seat on a direct flight from Boston to Orlando the frist day of April break (4/16) at this point); they would be pretty poor businessmen if they parted with those at a discount knowing that they can and will sell for full price at some point.
Good luck with your tickets!