We were there the week after Thanksgiving last year and they called guests at the Monorail resorts (at least) to let them know they would be taping the parade for the TV show starting at 8AM on Saturday (Dec 7, I think). We got there early and were part of the 'crowd' for the taping of the scenes as they approached the large Xmas tree. There was additional taping throughout the day, with all the celebs and a special day time version of the Christmas parade.
It was fun, and proved to be enough of a distraction for some that the Saturday crowd didn't seem quite a big as it might have.