I should point out that the AP rates - the "good ones" that we all seek (the ones under $200 per night) - are not doled out the same way or with as much frequency as they used to be. What the AP hotel calendar will show is simply the lowest available rate that you can get with your AP - but that may only be the standard 10% discount that is available 365 days a year. The actual "good rates" (they used to be called things like "AP7," "AP9," etc.) are going to be tricky to finagle for December. IN the past, the good rates would come out maybe 3 months in advance, and they could cover a good number of days.
But since DLR's attendance has gone up, suspiciously, the AP rates have became harder to come by in December. If they expect certain periods of time to be super-busy, they won't release great rates. They tend to release good rates for times in which they they are expecting lower crowds.
Last year, I visited DLR in early/mid-December and I checked that AP calendar for good December rates all the way up to late November/early December, and nothing good ever appeared on the calendar during that time, although the AP section of the DLR site itself was offering a special promo for the PPH (something like $168 per night, I think?). My dates were within the range of what used to be covered by AP's - the good rates generally go up to the weekend right before Christmas and then stop, and mine were well before that time. No good rates ever appeared on that calendar while I was looking.
I recall one of our other DIS'ers - Jenasweetemotion - saying that a couple of random December dates with great rates popped up on the AP calendar last year (for PPH), and she was able to grab the offer, and then it disappeared almost immediately. See, if there were still as many AP rates available for as many dates in December as there used to be, those dates that she saw wouldn't have vanished as fast as they did.
So IF there are any great AP rates to be had for December at all, they may not turn up on the AP site until right before you want to go to DLR, and if they do appear, they may be gone in the blink of an eye!