Apologies for the cross-post.
He found a piece of the TARDIS in the crack. My predictions are correct. I know what's going on, and this whole series is not what it appears to be.
Go watch Coupling. Observe Moffat's writing style, especially the episodes where he plays with sequential alternate viewpoints of various scenes showing how the scene is utterly different to what you thought it was (which he LOVES to do). Then think about Doctor Who, and consider how all his previous episodes (Blink, Girl in the Fireplace, Libraryx2) all involve a look at the time travel concept and manipulaton of that concept. He's never told a linear story in his life, in Doctor Who or any other show. The man's schtick is to show you things which are utterly not what they appear to be, and then later show you how it really is; and now he gets to do it in a show which actually has real time travel in it as the core concept. The whole series is a bluff (and not in a Dallas-style "it was all a dream" kind of way, but in a "when I add these salient details later you'll see it in an entirely differently way" kind of way).
We're in for a real shock. This whole series is a time travel story, and the reveal is gonna make us view all these episodes totally differently, because whatever we thought was going on wasn't going on. The "jacket" theory* (Time of Angels) and the other random theories are just pointers to that.
Watch Coupling.
Or watch the rest of this series of Doctor Who.
Basically he plays with the idea of showing scenes from one point of view, and then showing them from another and they're completely different yet identical, and tell an entirely different story. I can't really explain it, but it works and it's very clever.
The best explanation is to watch Coupling, see him do it frequently without the benefit of time travel as a plot point, then watch his Who episodes over the last 5 years, understand that for the first time he's responsible for an entire series' story arc, and realise it's all gonna be a time travel/perception reveal. Things we've seen aren't as we think they are.
This entire season is one time travel story. And we'll put it together later and wonder how we didn't figure it out earlier.
*Big spoilerific theory from fans who rewatch episodes a lot. Let's just say that it's fairly certain that there's more than one Doctor in this series, that we've seen evidence of such and probably not noticed it, but it will seem obvious later on in a Sixth Sense kick-yourself kinda way.