As others have said, the first two weeks are not as slow as they used to be over a decade or more ago, and after "911" attack and after the 2008 financial, home mortgage, job loss crash. And many schools have changed over the years from routine Thankgiving/Christmas vacations to year round school and home schooling offering many more different vacation schedules than before.
Another thing is that on December 6th is the official opening of Magic Kingdom's New Fantasyland section, so that might bring a lot of people back.
And the youth Pop Warner Football and Cheerleader championships have been coming at this time for over a decade. The 2012 Pop Warner Super Bowl and National Cheer & Dance Championships will take place from Saturday, December 1, 2012 through Saturday, December 9, 2012 at ESPN Wide World of Sports Complex. 64 football teams compete for National Championships and the Cheer & Dance Championships feature over 300 cheer and dance squads. Even though this sounds like a large group, most will be practicing for their games until they lose and then maybe go to the parks to enjoy themselves. I am sure the ESPN sports field areas will be busy.
And I guess the economy has gotten a little better, too, and more people in the world can now afford that WDW vacation, and maybe, they always wanted to go in November and December.
I think that the first two weeks in December are still better than Thankgiving week and weekend and during the Christmas and New Year's week and days.
I have been going to WDW for the first two weeks every year for over a decade and I have been lucky to be there when several Disney website groups were meeting up.
Last year the DISboard DISUnPlugged Podcast had a wonder December night at Universal Studios Harry Potter World all to ourselves after the park closed.
And there has not been an official "Mousefest" for years. Once upon a time, "MouseFest" consisted of many online Disney websites, Disney forums, Disney book authurs, all meeting together until it just got to big, I think. But last year and this year there are several planned groups called Reunion 2012 and R.A.D.P. Disney groups that are planning meets.
www.reunion2012.com/schedule Reunion 2012 is only meeting 4 days and 146 people have signed up. They are meeting from November 9- December 2, 2012.
http://meets.radp.org/radp17 Recreation Arts Disney Parks has been around before forums like the DISboards ever started and meet almost every year, too. They are also meeting for 4 days from December 7-10, 2012. The largest meet last year was about 100+ people.
www.themagicinpixels.com/2012/06/pixelmania-2012-announcement Pixelmania 2012 is another group of about 43 that will be having their Disney meets for for 4 days from December 6-9, 2012.
And there could possibly other conventions going on or other groups, but I just think that is could be that more people are able to go on vacations now than they were since the 2008 financial, home mortgage, job loss crash.
I am lucky since I can plan to go every year at the same time and make my reservation over 11 months in advance. I know sometimes it is difficult for me to get a BoardWalk Villa Standard Studio even when I try to make reservations at 11 months in advance with missing days reservations already made by others before the start of my reservation arriving date.
I really don't know the answer, but I hope that you get your rooms.