Actually, I do have a couple random thoughts that I will post (though they may have already been stated).
1) Clara was saved. Given the story, she could have easily been one companion that, once again, the Doctor loses. Rose, Donna, Amy and Rory...all lost to him. It was refreshing to see a companion finally make it out in one piece (or a billion pieces, whatever).
2) River Song. Will this be her last appearance? I admit that my hope for the character was to give her a multi-episode arc where it was just her and the Doctor traveling together, something to really solidify their relationship before finally sending her off to die in The Library. However, I was rather satisfied with the approach in this episode, coming at it from the perspective of her already being dead.
I have to wonder, though, don't you think the Great Intelligence might have some interest in the Biggest Library in the Universe? Could we see a return to that location?