Obviously this doesn't come as much of shock a bitter, cynical old man such as myself. But even I will freely admit that the audience for Doctor Who is a little broader than continuity obsessed middle aged hermits. So one of the many concerns that I immediately started having after Santa randomly stepped through the TARDIS doors at the end of the last series was how exactly they'd get away with having him in it and maintaining some semblance of coherent science fiction without telling the children of the world that there was no such thing as Father Christmas ON CHRISTMAS DAY.
As it turns out, they decided to go one better.
So.... yeah. INTERESTING sort of episode....