The new discount program will not begin in late December. The last two weeks of December are always blacked out for these tickets. When the program renews, it will begin the first few days of January.
As for Steve's speculation about the "late" tickets situation, we're coming up close on that at this point anyhow. We're already in mid-September. People can't even book their resorts at military rates for early next year, and most hold out for that, so the FP+ window is a moot point until they can. Myself and my colleagues all agree that the current promotion was mostly extended, not for FP+, but in order for Disney to get off of this Oct-Sept cycle for the program, and reset it so that next year's program runs on a calendar year instead, making it easier everybody involved to keep track of.
All that being said, historically the announcement about a new year's promotion comes appx. 2.5 months prior to the end of the current one. Since the current promotional rates/tickets will end Dec. 20, it's reasonable to expect an October announcement.
And believe me... If it's this month, as Steve's predicting, then I will be MORE THAN HAPPY to be completely wrong in this case. I have my own reservations for next year that have been made at Rack rate, and I'm itching to get the military discount applied before availability gets too slim!