We were there last year from 12/13/06 - 12/26/06....it was packed IMO the week before Christmas. I'm a "take your kids out of school" Mom to avoid the crowds. (1st and 2nd graders) Seems to me that everyone else thinks the same way now..that secret is out...having done the same with my older girls (now in college) in 1996 & 1997, I picked the week stated that it was "least crowded" in the guide books....and it was not crowded back then...we never stood in line. Returning in 2006 with the same philosophy was a big mistake. We barely waited during the first few days, but around the 19th, we waited. My older daughter and I commented the entire time on how it used to be...
With that said, I would never not go during Christmas because of crowds. It is the most beautiful time of the year and worth experiencing.
We all know crowds can be as unpredictable as the weather and the weather was fabulous Christmas 2006! 80degrees some days. It rained two days (they had a terrible storm) out of 2 weeks. The weather, coupled with the decorations and spirit, made the crowds bearable. In 1997, we didn't wait in line, but it was the coldest Orlando had been in years...it snowed!
Enjoy the time, just know it's going to be crowded, and hope for beautiful weather!...it is really a magical time of year at Disney.