I was let down quite a bit too. They must have spent all the creative juice on the Anniversary show and had nothing left for the Christmas show.
The fact that I watched the show wearing my "Exterminating in the Rain" tee shirt, armed with my Sonic Screwdriver and 11th Doctor Mr Potatohead, eased the pain a bit. I'm looking forward to Peter Capaldi's portayal of the Doctor now!