I bet you anything that River Song turns out to be either Romana or The Rani, though made human by a chameleon arch!
River was taught to fly the TARDIS. So was Romana by the Forth Doctor, as well as The Rani just being able to fly a TARDIS anyway. It would also explain (sort of) the other TARDIS sitting on Craig's house in "The Lodger".
I can just see Moffat ending this season like this.
It would be a great way to keep Amy from dying, by having her regenerate and not knowing why. Maybe she already did regenerate as a kid? Would be a good way to explain the eye colour change between her as a seven year old and her as she is now instead of just using the "could not find a red haired child with the same eye colour as Karen Gillan", lol.
Yay! Rory is back...as an Auton.
And, is it just me, or did the voice that kept saying "Silence Will Fall" sound like Davros.
We were promised Slitheen and Sycorax too. Come on Steven, deliver on those promises!
The 10th Doctor never really fought Slitheen so at least let the 11th Doctor have a crack at them! And I would like to see those "cyber ships", especially considering that the New Who Cybermen were from a alternate Earth where advanced space travel hadn't been achieved yet by them.