I've been here since Dec 1. IMO, the crowds are heavier than in past years. The first week of December was surprisingly crowded. (The posted wait for Soarin' was up to 70 minutes, and FastPass was gone by 2 to 3 pm). It eased off some the second week. (Posted time for Soarin' was 30 minutes, but we were on the ride in 15.) The park with the evening Extra Magic Hour gets big crowds. Still, as mentioned above, it's quite manageable. And it really is a special time of year to be here.
By comparison though, the crowds at USF, IOA, SW, and BG seem rather light.