All right, given that I have not posted anything on here in about half a year, let's begin afresh with something topical.
These can be separated into two broad categories:
A) Fanyay.
i) Given how much suspense and how many emotionally-manipulating teary scenes there were in this, I can understand why people who would never even consider watching, say, Davison era are regularly hiding behind the sofa nowadays.
ii) So it's canon that the Doctor's diminuitive is Theta Sigma now? This pleases me.
iii) Although the smug-bastard coalition of the stars teaming up to lock the Doc in a box is slightly stretching credulity (as has been noted elsewhere) the effect it produces is astounding. Creating a situation where Eleven's pretty much trapped in his worst nightmare, and yet is impressed - not to mention flattered - by the fact that his enemies called truce for him is rather more complex than you'd expect from kids' teevee.
iv) I've no idea what 'phi gamma upsilon delta possibly-lower-case-zeta-xi-or-theta' means, but I want to find out.
B) Wild Speculation about River, with gratuitous uses of the word 'awesome'.
I expect I'm the only person in the world who still cares about who she might be, now that the debate's been exhausted, but here are the options as my brain sees them, in reverse order of likeliness.
The Rani. Only because she knows Old High Gallifreyan, a bevy of timey-wimey science and the Doctor's Academy name. She is, on balance, awesome enough to be the Rani (possibly too awesome), but slightly too nice. Scraping the bottom of the barrel, this one.
The Master. Unlikely, but only because she is nothing like the usual characterisation (then again neither was Simm) and the entire concept is ridiculous. Given that she's from the future, essentially, this one brings up the possibility that there is a future-Master who a) has changed massively, b) knows the Doctor intimately in the future and c) is somehow trapped into travelling backwards along their timeline.
It's a good option in that it makes the Doctor/Master relationship an actual canon possibility, but also irritating in that it enforces heteronormativity by doing so.
The Doctor. A future incarnation breaking all the laws of space-time by moving backwards along her own timestream. It'd explain the intimate knowledge and the affection, but as the internal logic of Who stands, is impossible. And boring.
Time/the Vortex/the Untempered Schizm in a skin suit. Which is...possible, I suppose, Kronos was already a human-lookin' woman.
Future!Doctor's wife/partner/Oodsphere-significant-other. Again, possible ne probable, though slightly too obvious to make me happy.
The Anti-Valeyard. Only the most likely in my mind because it's the option that most interests me, but is very probably impossible.
Given that the Valeyard is the incarnation of the Doctor's worst traits, surely an incarnation of his best is possible too. This'd certainly explain how awesome River is: she has his courage, good humour, paternal affection, cunning and intelligence by her very nature. And if the Valeyard hates the Doctor then it's logical to assume that River loves him. Still, this is a wee bit sad-making because it takes agency away from River as a separate entity - were she the Anti-Valeyard then she wouldn't be an excellent person in her own right, she'd be so because the Doctor made her so by his excellent-personry.