Spoiler Level: High
A strong conclusion to a strong story. I'm very pleased that The Crack In Time And Space actually had a major impact on the main story, and that we got to learn more about it before the final story of the season, as it has been in previous years.
Ah, and River continues to intrigue. With every question answered, there's a question more. Okay, so she's been imprisoned for killing "the best man [she's] ever known." Well, to hear her talk, that would most likely be the Doctor. And with the Pandorica reference, we know we'll probably see her again at the end of the season. Makes me worry for Matt Smith's tenure as the Doctor, contracts or not!
And the more the season goes on, the more I wonder about Amy. I'm hitting the point where I'm not even positive she's a real human being, and not some kind of alien manifestation that thinks it's human but is really a trap for the Doctor. I know that's totally out of left field, but part of the reason for my thinking that is the final scene where she tries to bed the Doctor. What hit me about it is that she's trying to get the Doctor to indulge in immoral behavior (that fact that she's engaged, not the fact that the Doctor would be having sex, that's a whole different topic) on the night before her wedding, which is apparently scheduled on the same day as the event that causes The Crack In Time And Space to be created. Just makes me wonder.