Now this looks fun.
It's definitely not going to have the same flair as RTD's Christmas Specials, but then again anyone watching Doctor Who will understand the differences between RTD and Moffat.
This seems the same kind of Non-linear storytelling that was presented in the first part of The Big Bang. If the Doctor is the Ghost of Christmas Past, then Amy and Rory - given Amy's line to the "Scrooge" analogue - are likely subbing for the Ghosts of Christmas Present and Future.
There's obviously something going on that draws the three into changing this gentleman's outlook on life, and I'm very interested in it.
Is it a definite riff/parody/homage to Dicken's "A Christmas Carol"? Obviously. But it also seems to be a Character Piece, which is why I'm intrigued. While the Titanic, Alien Spiders, and Steampunk Cybermen might make for exciting television, there's very little about the actual spirit of the Holiday in them.
I'm game to see how this all pans out.