I must admit I was rather confused by Girl in the Fireplace and was watching that season of Who in a rush, so I probably missed the underlying themes and all that. What I got from that ep is that the Doctor can find people and then lose them again, and that such a thing might happen with River.

This whole ep felt weird to me, and I'm starting to like the idea that she's his biographer (as seen on some of the Who-comms) as opposed to a love interest. But all in all, the character just feels strange.

I hadn't thought about her knowing the Doctor's next incarnations, which would make sense. And keep her around for a while.

I should know better than to try and dissect half of a Moffat 2-parter -- we'll see how next week plays out (hopefully with more Donna)