I just watched it, and it certainly had some good points, like the clever resolution of the Silents invasion by
inserting a bit telling the human race to kill the Silents into the Apollo 11 landing sequence!
... but there were an awful lot of loose ends, which may or may not be tidied up at some point.
It also left me feeling rather unfulfilled, because so many things were left unexplained.
I'd just like a nice self contained episode, which doesn't have lots of obvious links to other episodes, like the aforementioned Blink, or even The Lodger, which it turns out is linked to this episode, but which does stand alone anyway.