You'll get to see at least some of the stuff, as Robo pointed out!

I would go out on a limb and say "most" of the decorations will be up, having been there during Christmas week before (
2007), as well as the halloween/christmas "switchover" week (
2012), I didn't notice much missing from the parks (in terms of decor) in early November vs December, though there were a few years between those visits. The large trees at the resorts may not be up then, and the special gingerbread houses and such likely won't be up at that point either, but a lot of the stuff around the parks will be - like poinsettias, wreaths, and garlands, as well as some displays like the toy soldier photo-op in the MK. Epcot likely won't have too much going on at that point though, aside from decorations, but over in Animal Kingdom you might be able to catch the first holiday parade. So you'll at least get the holiday atmosphere, but there are some "holiday happenings" that you won't get in on, unfortunately. It's an awesome time of year to visit though, enjoy!!!
