A few things I noticed. It was never stated what time the Angel sent the Williams back to plus River was quite demanding Amy follow Rory. I suspect there will be more from Amy & Rory to come. Honestly I would be shocked if they do not have some part to play "on fields of Trenzelor".
My personal theory is that they are sent back to the 1960's where they happen to find and raise a certain little girl that just escaped from her captives possibly with help from the Doctor. I mean the last time we saw young Melody she had just regenerated in New York. Somehow we need to get from there to Amy & Rory's hometown back in England. Obviously there is something there that needs to be explored since otherwise it just feels like an open wound, so to speak.
Hmm Now that would be quite neat ... I know they have done it a couple times already where they say they can't do something & then they do it ...
I kind of think we will see them again as well ... But man wtf ... we have only had what ?.. 3 episodes ... & now we have to WAIT ... LONGER ... As if breaking bads 5 episode season was not bad enough ...