Simultaneously, Rory, Amy and the Doctor fall asleep, only to immeditaely wake up in the Tardis. They figure the village was a dream, until they fall asleep again to awake in the village. Tardis, village, Tardis, village ... and so on.
A character calling himself the Dreamlord, explains that one world is real and the other fake. With deadly dangers in each world, "if you die in the dream, you wake up in reality." But of course, death in reality means precisely that.
So the Doctor, Amy and Rory are faced with a decision to make. Which world do they think is fake? Which existence are they willing to lose? Which world do they want to be their reality?
There's a similar decision when following Jesus:
If you cling to your life, you will lose it; but if you give up your life for me, you will find it.
We can choose to pursue the things of this life - power, material stuff, gratification, prestige, self-interest, etc. Or we can choose a reality based on love, integrity, compassion and something greater than ourselves. It's not just Amy's choice - it's our choice.