This episode was kind of boring, so I think I'll take the opportunity of this review to talk about how great Matt Smith is as the Doctor. He hasn't been in very many good episodes, but that is in no way his fault - he is excellent (as is Karen Gillan as Amy Pond, but that's a topic for another review of a mediocre episode).
First of all - his eyes. Matt Smith's eyes are amazing. No doctor has ever used their eyes so well. Whenever he is conversing with another person, his eyes are constantly searching their face, as if he is able to physically see into the other person's sould just by staring at them. He may be cracking some stupid joke, or delivering some tedious exposition, or listening to someone else crack a stupid joke or deliver tedious exposition - but his eyes never stop searching - his brain never stops working., no matter how stupidly he is acting.
And that's another great thing - the fact that it is all an act. The Doctor has realised that the best way to get people to pay attention to him is to act like a mad person who seems to know what he's talking about. So much of his craziness is a put on, so that the other characters feel both out of their depth and at ease.
I also really like the fact that he is a dick. He treats the people that surround him so blatantly like cattle for him to direct that he almost considers his own dickishness to be a big joke. No Doctor has been this brazenly jerkish to everybody near him since Tom Baker, but whereas Baker's jerkishness came in the form of an enjoyable smug sense of superiority, Smith's is more a general obliviousness to the fact that humans have thoughts or emotions of their own. It is really fun to watch.
But yeah, like I said earlier, the fact that it is really fun to watch the main character doesn't mean that it's really fun to watch the whole episodes. There have been a few good episodes with Smith, and hopefully the conclusion to this two parter will be good (it might be - this first episode wasn't terrible, just mediocre), but I'm not exactly holding my breath.