Let's begin with a quick recap of the Doctor Who season finale, "The Name of the Doctor”: Our heroes visit Trenzalore and check out the Doctor's uber-creepy grave. The Great Intelligence jumps into the Doctor's timestream to kill him at every moment in his history. Clara jumps in after him and saves the Doctor at every point in history, thus meeting every incarnation of the Doctor that we've met in his 50 years on screen. Then good ol' Doc jumps in after Clara to get her out. Oh, yeah, and River Song is already dead, and has been for a while. But that's not the important bit (apparently)! The important bit is that we meet John Hurt in the final scene. Here's a transcript for reference:
CLARA: Who is he?
DOCTOR: It's me. There's only me here, that's the point. Now let's get back.
CLARA: But I never saw that one. I saw all of you. 11 faces, all of them you. You're the 11th Doctor.
DOCTOR: I said he was me - I never said he was the Doctor.
CLARA: I don't understand.
DOCTOR: My name, my real name … that is not the point. The name I chose is the Doctor. The name you choose, it's like a promise you make. He's the one that broke the promise.
DOCTOR: He is my secret.
JOHN HURT: What I did, I did without choice.
DOCTOR: I know.
JOHN HURT: In the name of peace and sanity.
DOCTOR: But not in the name of the Doctor.
Then the title card: "Introducing JOHN HURT as THE DOCTOR."
Anyone else confused yet? I'm convinced that there's only one answer that makes sense. Let's break it down.
The laws of television
Ignore the wibbly-wobbly stuff for a minute. By the laws of television, Hurt is playing a character named the Doctor. There's no way around that. It's on the title card; it's clearly Steven Moffat's vision. Speculation that Hurt is playing the Valeyard (an evil incarnation of the Doctor), or the regular old dude from Gallifrey who ultimately becomes the Doctor, are really hard to justify when you see it written on the screen in all caps with that boomy "something big just happened" noise going on behind it.
The laws of Moffat
Moffat is many things, but he is not subtle Clara mentions the number 11 twice in this scene. In “Journey to the Centre of the TARDIS,” Clara just so happens to muck around with a giant book on the history of the Time War, like you do when you're lost in the middle of the TARDIS being chased around by something. We're going back to the Time War, like it or not. Even if our current Doctor does not want to acknowledge Hurt in his numbering system, Moffat wants us to ask that question in the days to come. Can a Doctor who does bad things be numbered among the Doctors?
The laws of spoilers
Hurt has stated that he plays "part of the Doctor" in a "kind of trinity," which includes David Tennant. Trinity is very interesting here. He didn't say as a part of a 12-man hit squad against evil-doers; he said trinity. We know that Number 9, Christopher Eccleston, refused to come on board for the anniversary special. Perhaps if he had, that trinity would have been the three Doctors of the modern era (a move that makes sense given the show's young fan base). However, the "trinity" language seems far more linked to fate, destiny and religion. And you know who loves religion …
The laws of the Silence
The Silence, the religious order that created River Song just to prevent the Doctor from going to Trenzalore, hasn't gotten a lot of attention of late. While The Great Intelligence clearly wants the Doctor to go to Trenzalore and answer the "First Question" (identified by Dorium Maldovar as "Doctor Who?"), the Silence did an awful lot of work to attempt to prevent those events from ever happening. Their prophecy runs like this:
"On the fields of Trenzalore, at the fall of the Eleventh, when no living creature can speak falsely or fail to answer, a Question will be asked, a question that must never, ever be answered."
A few things bother me about the prophecy: Trenzalore as we saw it in "The Name of the Doctor" has no fields. It mostly has graves and burny bits. So whatever "fall" happens there must occur before the planet gets destroyed. As in, we haven't seen it yet. Let's also look at the phrase: "no living creature can speak falsely or fail to answer." Everyone failed to answer the "First Question," except River Song. River is, by her own admission, not a living creature. "The Name of the Doctor" did not fulfill the prophecy. Those events have yet to take place. The Eleventh has yet to fall.
Moffat's latest story arcs have been by and large about tricking fate. The Doctor "dies" and doesn't die in "The Wedding of River Song." He skirts predictions, twists words and runs. So how can the Doctor escape his fate this time?
For one thing, he might not be the Eleventh Doctor. If Hurt fills in the gap between Paul McGann and Christopher Eccleston (as some have suspected), that makes Tennant No. 11 and Matt Smith No. 12. So the "fall of the Eleventh" could involve a great sacrifice by Tennant, allowing our current Doctor to escape unscathed.
My prediction is that Smith's Doctor must accept, acknowledge and number Hurt among his past selves in order to save his future. This fits with the themes of running from fate, only to find yourself at destiny's door. It also fits with the theme that we've seen over and over again in Clara: She appears in many times, in many places, but she is always herself. We're about to answer some questions about the nature of the Doctor. Is a man embattled, angered, "fallen," still the Doctor? We'll find out in November.