Okay, I was half right about River... I think this definitely was the last time The Doctor saw her, just not quite in the way I imagined.
"Broke his promise..." Okay, well... The Doctor said that "The Doctor"- the name he chose for himself- was a promise. A promise to do something, be something. A doctor is someone who helps and heals people. That was his promise. So, the one who broke the promise is no longer deserving of the name/title. They stopped being The Doctor. And The Valeyard was namedropped, so... it looks like a possibility.
The Whispermen were not as scary as I was expecting, although the line "I'm sorry... I think I've been murdered" did shake me.
And when the "John Hurt as the Doctor" popped up- something about that got me. Not so much the fact that he's playing The Doctor since I'd already seen rumours, just the way they did it with the text. You don't expect actor titles to just pop up like that at an insanely tense moment, and it was genuinely surprising and very, very effective.
It amuses me somewhat that The Doctor was already an old man (well, not really by Time Lord standards, but his body had grown old) in his first incarnation when he first stole the TARDIS. The scene was well done, too (Was that found footage, or the guy who's playing Hartnell in Mark Gatiss's docu-drama?) Some of the footage edits weren't so well done, but it's a great concept. The Gallifrey version of Clara implies that not all of her incarnations were human, and at least one of them was a Time Lord. Not that it's likely to come up again, but, still- interesting idea.