Yeah and the resorts are all decked out. Be sure to visit the Grand Floridian to see the Gingerbread house and giant Christmas tree. The Wilderness Lodge is also elaborately decorated. (And I’m almost sure the Animal Kingdom Lodge has a giant Christmas tree, as well.)
Along with the Christmas festivities, there’s a lot of New Year’s happenings. Each park (excluding AK) has a special fireworks celebration. DHS has two stages - one with a live band, the other under the Sorceror’s hat has a DJ. MK is always packed with guests waiting to ring in the New Year. All parks hand out hats and blowers in the evening (they get annoying after the first 20 minutes of honking…). I highly recommend late evening ADRs to take a break from the noise.