|An outfit we can be almost positive Capaldi isn't buying|
Apparently, Peter Capaldi's busy right now trying to decide on his planned outfits as the Doctor (is this a hint that Capaldi's not going to be in the Christmas special at all, a double-bluff to make us think he won't be in the special, or a reward to the actor for waking up in a bow tie and a fez? Be nice to see a fez again before Smith leaves.)
"He was texting me ‘I’m out with [the wardrobe stylist] at the moment, it’s going quite well’ and some descriptions of clothes I did not understand. If it’s not a suit…I’ll just let them get on with it and it’ll be ‘yes’ or ‘no’ at the end. He likes his clothes, he’s got very strong opinions about clothes, he’s very dashing."
Moffat also indicated he was interested in the prospect of a crossover with Star Trek, with the general enthusiasm of a man who knows he's answering a fanboy question and probably won't be called upon to pull off this messy legal and technical tour de force in reality.
“Star Trek and Doctor Who together? It would be brilliant fun, but I can’t imagine us little lot in our leaky shed in Wales and a mighty [Hollywood] studio – can you imagine the meetings alone?! I’d do it – I can’t imagine they would. I can’t imagine they would do it, because they’re too protective. I would do it in a shot – of course I would!”
Finally, and most intriguingly, he's saying that while the Doctor can only regenerate twelve times, that's not the end of the story. “I think you should go back to your DVDs and count correctly this time," said Moffat, "there’s something you’ve all missed.”
That's it. That's all we've got. Obviously, it's open season trying to figure out what he's on about, and the Radio Times comments thread for the article has already gone through most of the obvious possibilities. These include "does he still have leftover regenerations from River Song from 'Let's Kill Hitler', then?", "the Time Lords didn't call it a regeneration when they changed Troughton's face, maybe that one really doesn't count after all", and "didn't Matt Smith already say he had 507 regenerations on SJA?". The oddities of the Time War and "Brain of Morbius" don't explain a word of this (the one isn't on DVD and the other compounds the problem), but you do rather have to mention them in a discussion of mysterious regenerations. And that's before people started on about the Valeyard, and pocket watches, and the "complete new life cycle" line from "The Five Doctors", and What About Zygons, They Imitate People, and several other entertaining lines of discourse. We could probably keep this up until Smith's regeneration.
Unless Moffat simply meant to indicate that Capaldi is going to be the last Doctor because of Hurt's existence making him the Thirteenth Doctor after all, and not the Twelfth (except when he's not the last anymore when the show has to keep going, but that's a side point). Either that or the River Song Saves The Day explanation probably accounts for matters, but speculation's such fun anyway.