Not quite what I expected based on last week's teaster- take that for what it's worth.
Loved the "Mission Impossible"-esque sequence. "She's gone out the window, then?"
Some really nice character moments, as usual. The Doctor's "date" with the slitheen Blon, in particular, makes me seriously question anyone who thinks that previous continuity of the series has been tossed out the window- the Doctor's reaction, as well as the subtext of the scene, really (IMO) is based strongly on the Doctor's past life decisions and actions, and Eccleston really portrays the anxiety of the moment very well.
"Bad Wolf" surfaces again, and far more prominently than ever this time. Really enjoyed Jack Harkness' character this episode. Don't know what they've got in store for him, but based on last week's episode and the fact that he's in the next two (final two) of the season, I think his story is deeply tied in with the Doctor, and I wouldn't mind seeing him stick around for the next incarnation of the Doctor, especially with Billie "Rose" Piper slated to leave early on next season.
Very low key episode, not a whole accomplished, though I have to admit I absolutely love how tight continuity has been this season as a whole. Really awesome, and I hope they keep it up going into the next season (Gwyneth as the reason for the rift? Tight.)
Should go without saying that the preview for next week is awesome. We should get all the answers we've been looking for very soon.