Now that the End of Time, Part I episode of Doctor Who has aired on US television, I can give a more full-throated, spoiler-laden review with a clearer conscience.
The episode is the first of a two-part swan song for actor David Tennant and writer Russell T. Davies, who championed the classic show’s revival and provided its major stories. Like previous Davies-penned Christmas shows, this one was a big, pregnant piñata, stuffed with complex and long-simmering storylines. Beloved heroes and villains return, mixed with new and interesting ones. Many of my fellow Who fanboys harshly criticize Davies for this heavy, baroque brush; indeed, some of the reviews on io9 are downright brutal.

I am not one of these critics. I think that Russell T. Davies approached his tenure as head Who-scribe in the manner of a 19th-century novelist: his individual episodes are standalone adventures, but they also form part of a grander whole. The End of Time appears to be providing resolution to plot lines that began during the first series of the reboot.
The first and most epic of these meta-plots is the Time War, a historically-frozen holocaust that destroyed all of the Time Lords except for the Doctor and the Master. As a “time-locked” event, the Doctor is powerless to prevent it. In The End of Time, we see the doomed Time Lords scurrying to prevent the inevitable. But as we saw in The Waters of Mars, time has its own ideas — and it has no problem handing down a humbling smackdown, even to a mighty Time Lord. The End of Time asks: will the Time Lords be able to undo their extinction, or will their meddling bring “an end to time itself”, as prophesied by the Ood?
Which brings us to another meta-motif in the Davies episodes that is marching toward resolution in these final shows: the “sound of drums”. In series three, the Master is obsessed with a martial drumbeat that throbs in his head, and he uses it to enslave humanity. We assumed that this was just the Master’s psychotic time signature, the pulse of his madness. But the latest episode hints that it is much more than this — the Doctor can hear it, too. Clips from Part II reveal that the pounding is the beat of the Time Lord’s two hearts; a signal broadcast throughout history by the desperate and doomed Gallifreyans. It is also the “four knocks” that foretell the Doctor’s impending “death”… however that is going to play out.

Part I was also full of lighter confections — like the revelation that the Doctor dilly-dallied en route to the Planet of the Ood, marrying Queen Elizabeth I along the way. Apparently he robbed her of her prized “Virgin” epithet — this explains Liz’s rage upon seeing the Doctor in The Shakespeare Code.
Special props must be paid to director Euros Lyn. His direction is a perfect mixture of brisk action and moody foreboding (see Torchwood: Children of Earth for the best example).
I think the RTD haters should back off a bit — try to see this elaborate effort as a truly Grand Finale to a great run at the Who helm (and hey, at least he didn’t include the Daleks* — yet).
* Not that I would mind…:)