Last year was a little weird because of the "Best Rate" plan Disney was trying out (and has since discontinued), but here what's December showed for discounts:
Check ins between 10/5/05-12/25/05 Florida resident room-only code became available on 8/25/05, exp 12/25/05
Check ins between 10/15/05*-12/19/05 Annual Passholder "Best Rate Program" (*program supposedly started 10/8/05 but required 120 day advance purchase, so first check-in date actually bookable was 10/15/05) 6/17/05
Check ins between 10/23/05-11/23/05 "available to anyone" room-only code became available on 9/29/05, exp 10/22/05
Check ins between 10/23/05-12/25/05 package discounts for general public became available on 9/29/05, exp 10/22/05
Check ins between 10/24/05-12/25/05 Annual Passholder "Best Rate Program" changed to 60 day advance purchase 8/25/05
Check ins between 12/20/05-12/25/05 Annual Passholder "Best Rate Program" 8/6/05
Since the BR plan kind of skewed those dates, if you look at 2003/2004 it might be closer to what will be offered this time:
2004
Check ins between 9/30/04-12/25/04 Annual Passholder room-only rates became available 8/25/04, exp 12/25/04
Check ins between 9/30/04-12/25/04 "available to anyone" room-only code 8/26/04, exp 10/10/04
Check ins between 9/30/04-12/25/04 package discounts for general public 8/26/04, exp 10/10/04
Check ins between 9/30/04-12/25/04 package discounts for Disney's Visa cardholders 8/26/04, exp 10/10/04
Check ins between 9/30/04-12/25/04 Florida resident room-only code 8/26/04, exp 12/25/04
Check ins between 9/30/04-12/25/04 "available to anyone" room-only code promoted through McDonald's restaurants 9/16/04, exp 10/10/04
2003
Check ins between 10/2/03-12/26/03 Annual Passholder room-only rates 8/28/03, exp 12/26/03
Check ins between 10/2/03-12/26/03 Florida resident room-only code 8/28/03, exp 12/26/03
Check ins between 10/26/03-2/11/04 Winter Settler rates for Ft. Wilderness campground - 21 night stays or longer 5/29/03, exp 7/20/03
Check ins between 11/10/03-12/26/03 package discounts for general public 8/19/03, exp 9/22/03