Weve gone the last two decembers and let me say BRRRRR... We are from ohio, so we are use to cold winters but a few times, those 50 degree days at Disney were downright chilly. There was not a time either year that was warm enough for us to swim (although a few kids were always in the pool)...In fact, we never wore shorts. A few days, it was low 70's and just gorgeous out for t-shirt and pants, while other days, we had winter coats, gloves and hats. There was even one night they nearly got a frost! It was still warmer than Ohio, but I had the misconception that Florida was always toasy warm...and that's just not true. Last year, we went Dec 1-8, this year it was Dec 8-18.
We found that last year, we were there the first weekend in december and it was packed because of parade taping. This year, we came after the taping weekend and found it not bad at all. In fact, a few nights on the EMH's, it was like a ghost town. The only day that was aweful was our last night (sat 17th at MK PACKED!) and the 19th we found much more traffic in the parks as well.
As for rates, For 2006, here is the breakdown on seasons:
Value Season: January 1 - February 15, August 6 - November 16
Regular Season: April 23 - August 5
Peak Season: February 16 - April 22
Pre-Holiday: November 17 - December 19
Holiday Season: December 20 - December 31
We found our pricing not much higher than value season...they go up when holiday season starts as does park traffic.
The Christmas party is awesome, we loved it, and the decorations are amazing. If you havent been to disney at Christmastime, its a must do!