One thing that I have always liked about this Christmas special was the fact that it wasn't an episode of Doctor Who that was swamped with Christmas goodies. Instead, it is more of a Doctor Who story set during Christmas. Apart from a few "Merry Christmas" remarks, the episode chiefly stayed clear of any outright Christmas inserts. I have nothing against Christmas, but some of the specials have seen their share of Christmas overdoses to the point that they directly affect a good storyline. "The Christmas Invasion" for example. Killer Christmas trees? Really?
I do think that the episode could have been titled better, even though I'm fully aware it was more or less a publicity stunt to ensure fans would tune in. It's only fitting that Davies would tease fans about The Doctor's next incarnation, since his flirtation with regeneration in "The Stolen Earth" and "Journeys End." But the idea of calling it "The Next Doctor" when in fact Morrissey isn't really the next Doctor is bit misleading, if not pointless. A pity though, in retrospect, because the first time I watched this episode I remember thinking what a great Doctor Morrissey would make.
With the misleading title aside, this episode offered a very deep mystery for The Doctor to solve. We soon discover that the Cybermen are at work, but WHAT they are up to, and what Miss Hartigan's involvement with them is were questions we were frequently asking.
Davies wins more WhoScale points with this one by writing a Cybermen story that only uses three to ten Cybermen in frame at any given time, and no CGI wide angle shots with a jillion Cybermen in the background.
The cemetery scene was nicely done, with maybe one small oversight- two Cybershades hold a man captive while a Cybermen shocks him. The electric charge doesn't seem to affect the two Cybershades.
The episode does take a small downward turn though in the last twenty minutes, where the underground factory scene begins to look like Indiana Jones and the Temple Of Doom merged with a West Side Story musical. Also, the moment the CyberKing arose from the Thames and started marching over Victorian London, I immediately thought, "Go, Go Power Rangers." In Doctor Who's defense, this isn't the first time the Doctor has dealt with giant robots, but it only works when it's tastefully and carefully done, so that it doesn't look like a Victorian Megazord.
My only other complaint with this one is one that is frequently repeated in my reviews of the new series. The orchestrated music. This is another element of Doctor Who that can work if it's done correctly, but in the case of this episode - where a musical score seems to accompany the entire length of the episode - it's just too much music, especially in some quiet, passive dialogue scenes where it was really unnecessary. In those scenes, the dialogue nor the story was trying to invoke an emotion, we were just listening.
Overall, I thoroughly enjoyed it, and often found myself thinking how different the pace and story of this episode was compared to the last two. Probably the biggest Christmas present Davies could give any Doctor Who fan in an episode was the montage of all ten Doctors. The episode opened with a lot of questions, but Davies was able to answer them all slowly and effectively through the course of the episode, and all the explanations made logical sense. Definitely a positive change from the last season's finale.