We were there last Christmas (2007). We got to see and do so much, I credit that to the fact we set about getting to the parks early. We all got to the parks just after opening and the crowds were not bad then. We seemed to get all we wanted to do and see by the time our ADR's rolled around we were in need of a rest. Since our kids were 15 yrs and up, usually after dinner, hubby and I would head back to the resort and the kids stayed a bit longer. Some days we stayed longer and saw some of the night attractions. The parks seemed to be so much more crowded then. Also one thing we did was hit the things like Test Track, Soar'n, Tower of Terror etc early or get a fast pass. Usually the kids would head to the faster rides, then get a fast pass upon exit so they could return later for a second time at the ride. Sometimes we sent our Key with them so they could also get a fast pass for us and we all returned together. I have trouble walking and can not do the wilder rides, so this worked out well for us. Basically, head to the parks early and once in head to the "have to do" rides first. Then we usually headed left when going thru the parks while the bulk of people headed right.
Have fun!