A nice slice of a sci-fi staple theme for this episode - the inhumanity of humans, and as RTD pointed out, they had to do an ice planet. The interesting Poe-esque come-uppance was a bit ... well,.... anyone go off their spaghetti?
I missed the fact he was an Ood underneath when he peeled back his scalp. I thought he'd exposed his skull until he vomited up the tentacles.
On another note, it seems that this Doctor has the ability to do a Vulcan mind-meld, now where did that come from? Has he done this in previous incarnations and I've just missed it?
I agree with the whole 'neatly tied up by the end' thing. It is unfortunate that it is apparently the current TV climate, where people these days have the attention span of a relatively dim goldfish, leading to programming guidlines being tailored accordingly. To think that people won't be able to follow a story over a few weeks is a bit silly, but they cited that the old Doctor Who format wouldn't survive in todays fast paced media environment, as witnessed by the demise of the series during Sylvester McCoys' reign.
As for the song ending.... I don't know the outcome, but just wait until the last two episodes is all I have heard... much bigger than the 'end of the world' stuff apparently.