We went Dec 1 - 15 2004, and had a wonderful time. Really missed our Disney Christmas this year. All the decorations are up , and I can still hear "It's the Most Wonderful Time Of the Year" which seemed to be playing everywhere. All the parades have a Christmas theme, the trees are great, adn the Osbourne Lights were fantastic. We did
MVMCP twice it was so cool wandering round the parks with hot chocolate in the dark... also got loads of great Disney Christmas decorations.
The first week we were there it was quite warm, but not hot - warm enough for shorts/ t-shirts, but you need a jacket in the evening. Second week we had a cold snap - lovely and warm in the sun but about 10 celcius in the bitter wind, needed our jackets all day. Then it went back into the seventies again and we headed for Blizzard Beach, but of course the only other people there were hardy Brits like us....
Crowds were low, though a bit busier at weekends, and we saw the Pop Warner cheerleader folk everywhere but they are quite well dispersed in the parks. Different story if you are in the same resort as them though I think....
Really glad we went in early December, won't be able to do it again as we can't take the kids out of school.