I've read that Christmas TV being a big thing is (or was) pretty unique to the UK, is that right?
As for River Song, there are plenty of theories - the wife thing seems too obvious since it's been signposted so much, but with Moffat writing I don't think that means we can rule it out. A popular theory at the moment seems to be that
she's Amy and Rory's daughter, with the pregnancy also being their exit storyline. I'm more interested in his assertion that something from the first episode of series five will be important in the next series, and it's been staring us in the face apparently
