I also agree that it was overwrought. It overshot by killing off all the main characters immediately, so it had to be some sort of reset button (also, not sure how I feel about the kid's segway having a built-in machine gun, and I definately don't think he should've been firing it from right behind one of the soldiers. Bad blocking). I thought the "ordinary person is the most important person" was about as well-done as RTD has ever hit the theme, with the added message that things become important because we make them important, though the part about her pointing at the street sign and that somehow connecting to Ruby being named Ruby was... wacky. The Doctor also seemed a bit too broken up about killing Sutekh (he's done the same thing to people he's liked better), especially since he'd already done it, in that exact way, once before.
I feel like there's a shoe yet to drop with the 73 yards thing, because it just raised further questions by revealing that's the range of the TARDIS Somebody Else's Problem field and that outside of Ruby's bubble universe, the Doctor had a front-row seat to Mad Jack's fall (maybe he is the Minister of War, after all).
I don't know why everyone is saying Mrs. Flood is River. She's probably Clara. She was wearing a similar outfit to the one Clara died in, she called the Doctor "clever boy" after he double-negatived death, and Moffat is writing the next episode, and I'm guessing it's not just because he's better at Christmas. Though, Flood's closing narration, about "that mysterious traveller in time and space known as the Doctor" is almost word-for-word how Missy introduced herself playing the Doctor in "World Enough and Time," and that her reaction to impending death was to find the nearest religious person and tell her to let the man upstairs know that dying just means she's going to become God's problem is very Master-ish.
And the Master is still up in the air, last seen in a gold tooth after dying under indeterminant circumstances that may or may not have been when we last saw him, and Clara did have a... complex... relationship with Missy, which may not have been helped by the fact that the Master may have screwed Clara, and all of reality, if he destroyed Gallifrey before she had the chance to come back and get returned to her death.
So, laying down my markers for six months from now, from most to least confident, I'm going to say, the Master/Missy, then Clara, with a chaser that "the World" which joy is being brought to is not Earth, with a longshot bet that it's Gallifrey.
