AP discount codes were available for vacations beginning on 12/25 or 12/26 for the last several years. As long as you checked in for that day, you received the HEAVILY discounted room rate for the entire vacation, including NYE.
However, Disney only released AP rates through 12/23 for this year. That does not help my family, and we more than likely will not be down this year b/c we will not pay rack rate during holiday period.
Still anxiously checking Swan and Dolphin, they sometimes won't have any dates blocked out. But right now, their only AP and teacher discounts are only for suites during those travel dates.