I liked it. It riffed on [spoiler]Curse of Fenric[/spoiler] quite a bit in the climax, but I quite like that one, and I also like the contrast: [spoiler]#7 acted like a raging prick in that one to shake Ace's faith in him, while here #11 was, I think, being totally honest.[/spoiler]
(Also did the clown remind anyone else of Colin Baker?)
[spoiler]Pretty sure I read Gillan had renewed her contract. I don't think this is a real goodbye; I think it's just necessary to establish what we already know: the Doctor's going to ramble about the galaxy for 200 years before he comes back. Though if the guy from The Lodger became the new full-time companion I wouldn't complain.[/spoiler]
Themes we're seeing over and over again: prison and Hell. River's in prison, and the people who were after her wanted to send her to Hell. And of course we know she eventually goes to Heaven.
Is the prison itself a kind of hell? Would that explain why they keep letting her out and why she keeps coming back? Perhaps the ultimate punishment for killing the Doctor is to allow her to know and love him.
We've also got fear and duality. We're clearly meant to believe that the Doctor is his own worst fear. (And, presumably, the thing he holds the most faith in. Or would that be the TARDIS?) He confronted himself as the Dream Lord last season, and we've had at least two episodes this season which featured duplicate Doctors. (And one that featured a duplicate Amy, of course.)
Where's it all going? Dunno. But two weeks doesn't seem like much time to tie up the loose ends, and I'm beginning to fear we'll be left with more questions than answers.
Purportedly next season's going to be short -- the better to prepare for a big 50th anniversary event in '13.