If you put the Smilers and the Silence together, you get the Gentlemen. Or really, if you take the Gentlemen to start with, you could derive either the Smilers or the Silence, or as many identical things as Moffat can "imagine." In some ways it's nice to see him ripping off people other than himself, one supposes.
Which, there's a sort of half-formed thought here about how the Silence and the Weeping Angels are the same thing, so maybe the differences between them are what's important? I mean, as far as where this is headed. The Silence don't seem to have much to do with the concept of silence, nor really the Crack, both of which seemed to figure largely before now.
In fact, I'm more confused than ever as to their gameplan. They're advanced/powerful enough to destroy the vampire-fish planet, right, and the Prisoner Zero thing seemed scared of them, and maybe they can make a DIY TARDIS or two...
But they can't build anything and they can't make anything without forcing Americans to do it for them, through mind-control. And now their plan also seems to involve building a spacesuit in 1969 for Amy's baby, or whoever that little girl is, which she can escape at any time? Is this related to the Lodger thing? And why were they involved in the exploding TARDIS issue last year? And why did the TARDIS explode/universe end? Didn't they say there was more to that part? Am I just an idiot that can't remember why the Crack happened?
I'm so confused. They're so easy to kill, and yet they seem to have a bunch of plans happening at once. This could be brilliant misdirection, or it could be an episode that doesn't ever come up again. You just never know.
Remember back at the beginning of the episode, Canton locked himself in the unbeatable prison with the Doctor and two bodybags. Well, you could be forgiven for assuming that wouldn't come up again, but now here they are, days later, opening the door and strolling out. The military dudes give them shit about it, but must contend with the double whammy of both Canton and then ("Hail To The Chief" again) Nixon telling them to shut up and stop interfering with the Doctor, just like in every scene.