Immediate reaction.
I WAS FUCKING RIGHT.
Okay, I was about 2/3 of the way right. I bet with a couple of pals that 1. baby was absolutely Amy and Rory's, 2. the baby was River, and 3. the bb!Time Lord at the beginning of S6 had nothing to do with it.
OH SHIT OH SHIT OH SHIT OH SHIT OH SHIT.