We were there 12/18-12/28 last Dec. '04. To us, the days were erratic...I remeber thinking the 20,22,23,24,25, not bad, but 18,19,21, 26-28 pretty jammed. However, we arrived on a Sat which is always crowded and a whole new crop of folks then as it is when just about every school lets out for break. We expected awful crowds on 24, 25...but the weather was cold and rainy and that kept the crowd level down. Our kids are 10 and 14, so we took advantage of the late hours on Xmas eve and hit MK from 10:30 -midnight...just about everything was a walk-on. We were kinda teasing ourselves tho, as since the weather was so crummy if we were at home, NO WAY would we be at a Theme Park with winter coats/ponchos on due to lousy weather...but we had just eaten a FAB meal at O'Hana's, gotten on the monorail, and MK was right there...it was a blast! We hit Epcot/MGM on the 25th...again, rainy day, but very manageable crowd wise. On the nice day 22...it was jammed everywhere! So, I guess what I am trying to say is, the crowds WILL be there that week, but you may get lucky and have some breaks. Also, even tho we are not early risers...we forced ourselves at least 1/2 of the time to get up..it did help. We specifically did a split stay WL first 4 nights and the Dolphin last 6 for the locations...it was great strategy that paid off once the crowds were there at the end of the night...we just walked to the Dolphin. I will say that the cold was rough tho...when we take our next trip, we will plan for summer..but on the up side, we were not tired from lugging backpacks/water bottles etc. around the parks all day.
Have a great time!
PAM