- At the beginning of "Asylum of The Daleks" he tells Amy "Make them remember you."
- At the end of "Asylum of The Daleks" Oswin says "Remember me."
- Amy had a Time Lady baby, River Song.
- How did that happen if she wasn't a Time Lady?
- In "Dinosaurs on A Spaceship" Amy is really, really good with technology.
- Remember who else was really good with technology?
- That's right, Donna Fucking Noble after the metacrisis.
- Oh, yeah, and Oswin.
My money is on "Amy somehow became a Time Lady and regenerates into Oswin."
If I'm wrong, meh. I'll just write an AU fanfic about it.