The Free Dining offer, which covers up to Christmas (with many restrictions and black out dates) has already expired for a booking window. I believe there is another holiday discount out that gives 10-20% discounts on room rates that you can book thru 10/7 (but I think that is the one people say there is no room availability, so why did Disney even bother).
Historically, the discounts for post December usually are not released until sometime in September. A common discount is the Stay-Play-Dine package where you purchase all components (room & tickets & dining plan) under one umbrella package. Its not as good as Free Dining, but still offers a decent discount. Then there are usually standard discounts off of rack rates, which would vary by resort type and room levels.
