The previous posts are right on the money!
We've been there just before Christmas for the past 2 years and it was truly incredible!
Way too much to list here. If your not in the Christmas sprit when you leave, shame on you.
However, if you do go in Dec, I would highly advise you to decorate your home for the holidays prior to your trip. After, our first trip in Dec 02, (we didn't decorate) and came home totally depressed. We left our Christmas sprit on Main Street. The following year (03), I had the outside lights up on Nov 1st and the house was fully decorated by our departure (Dec 5th).
What a difference that made!