So much Christmas music- we just got back on the 27th and I still have all the Christmas tunes and Nutcracker music stuck in my head. We stayed at the Boardwalk. The music in the elevators and common areas (elevator landings and lobby) were always on. So was the background music in most parks- I'm definitely thinking MK and Epcot. In AK, we didn't hear so much Christmas music, but the regular AK soundtrack.
We also enjoyed the World last year in the beginning of Jan (after the New Year's rush) and we were serenaded with Christmas music in the parks still (like the walkway to and from the park entrances). The major Christmas trees in the parks (the ones in front of every park entrance) were also still up.