Very quickly, because everyone's probably already said everything but I only got round to watching it last night ...
It was very Star Trek, wasn't it? Specifically the third fillum and that DS9 one where they stranded Nice Bajoran Religious Lady in the Gamma Quadrant so that they could have the subtle, nuanced conflict between Creationist-Analogy Other Bajoran Religious Lady and Kira's Bajoran Religious Boyfriend. Who do you think we're supposed to like, boys and girls?
For once, I actually want to know the authorial intent (but only because I've heard too much in advance about it, if that makes sense). What's the major epic change to the Doctor's character supposed to be, then? I can't work out whether the ep is supposed to leave him more or less emo or what.
They're going to have to tie Martha's characterisation into a pretzel to reconcile this "OMG so depressing I'm not getting involved in that" business with working for UNIT/Torchwood on pretty much the exact same sort of thing just on Earth.
Oh, Donna, you're so doomed, aren't you? Why did you say the f-word? You don't get to stay forever, that's what the whole damned show has been about. Though I am shipping you even harder with Martha now and clearly whenever you get back to contemporary Earth there are going to be companion booty calls.