This is adapted from the text of my review for the Rift:
Since the show's relaunch in 2005, the BBC has aired a Doctor Who Christmas Special every 25th of December. The results haven't always been Who at its best. 2005's "The Christmas Invasion," David Tennant's first full story as the Tenth Doctor replacing Christopher Eccleston, was a bog-standard regeneration story, and it doesn't particularly hold up well, since the whole no-mercy-no-second-chances thing was abandoned within an episode or two of the 2006 season, as it didn't really track with Tennant's daffy portrayal.
2006's "The Runaway Bride" was half a good story, but to get to that half, you had to suffer through the get-her-to-the-church-on-time nonsense with Catherine Tate's Donna Noble at her most shrill. After the wedding, things settled down nicely, and you can see the beginnings of the magic Doctor-Donna chemistry that we got in the 2008 season--but man, that first half is hard to plow through.
2007's "Voyage of the Damned" was basically The Poseidon Adventure in space, and it certainly had its moments, but it was mostly disposable fluff. Also, Kylie Minogue's Astrid was the third straight pretty young thing who got all dewey-eyed over the Doctor which was, to say the least, wearing (and made Donna's return for the '08 season something of a relief).
This year, we have "The Next Doctor," a story that gives us the Tenth Doctor in London on Christmas 1851 (a year he describes as "a bit dull," which is always the kiss of death), who finds himself encountering an unfamiliar man who calls himself the Doctor, has a sonic screwdriver, and says "Allons-y!"
"The Next Doctor" is like a meringue--it tastes nice, but doesn't really leave you satiated. Having said that, I loves me some meringues, so I ceratinly enjoyed myself. A lot of this is due to David Morrissey in the title role, as he and Tennant play together beautifully (the two of them also paired up in the series Blackpool), and the more we learn about this new Doctor, the more we like him. Velile Tshabalala is criminally underused as Morrisey's companion, Rosita, but she makes the most of her screen time, to the point where you really expect her to hare off in the TARDIS when it's over.
The bad guys are the Cybermen, which is the real problem, as the Cybermen have never been the greatest Who villains, and they've been particularly nowhere in 21st-century Who. The cybermutts are embarrassing—hell, I'd rather have had the cheesy old cybermats than these goofy guys-in-fur-with-cybermasks—and "Delete" remains the world's most unintimidating battle cry.
Because Cybermen are boring, we need a human bad guy for the Doctor to have non-monotone conversations with, and while Dervla Kirwan—last seen alongside Tennant in Casanova—is quite delightfully evil, her character of Miss Hartigan manages the neat trick of being a symbol for empowering women and sexist twaddle, all at the same time. Which, I guess, is an accomplishment. Sort of.
Finally: steampunk clockwork Cyberking? The Doctor facing same in a hot-air balloon? Bliss. Yeah, it's so over the top everyone's nose should be bleeding, but who gives a smeg?
While I look forward to the day when one of these holiday specials has more substance than a Christmas pudding, I'd say this was the most enjoyable of them thus far.