What the frak?! Gyah, I was _not_ prepared for a "to be continued." Donna's grandpa is familiar. Do we know that actor from somewhere else? Oh, he reminds me of the dad on Frasier. That's probably it.
Hee, Martha's engaged to Tom! Too bad it's a rebound. Parallel with Gwen and Rhys getting engaged while Jack was away? Hm. Anyway. I spotted the ring, and at first didn't think anything of it because Martha usually wears rings. But ring_s_ plural, and now there was just the one. Hmmm. And yay I was right! and the Doctor was adorably oblivious. *squishes him*
Donna continues to be absolutely fantastic. Especially when she's calling him on being adorably oblivious (not that she puts it that way, of course). And when she's being clever and figuring out something is up with the workers.
I'd read speculation somewhere that the tank seen in the trailer was for cloning, which I thought was a cool idea but a bit farfetched. But um, yeah, I guess not. I'm glad the speculation wasn't _completely_ true, as the thought was that UNIT was cloning companions for some reason, to which my thought was that perhaps Rose's return then wasn't really a return and maybe she was just a clone? Which wasn't really a happy thought. Anyway.
Anybody else see something bad coming down the line for Rattigan once the Sontarans have no further use for him? (And who else instantly thought of The Great Mouse Detective when they saw the name?) He's a traitor and therefore obviously can't be trusted, and there must be plenty of other geniuses (genii?) out there the next time they have some dastardly plot to wreak upon an unsuspecting world.