One thing I think this episode finally puts to bed is thus: regenerating is an inherited trait unique to the Time Lord species, and not persay, a technical thing that Time Lords undergo after graduation.

Because the technical thing line was the predominant view for many, many years in fandom, was it not? Now, I suppose Moff could later pull a trick out of the bag and say that The Girl is bio engineered - and he's certainly left himself plenty of outs on that front, but we're clearly meant to be speculating whether or not that's the Doctor's daughter via River or Amy.

(One speculation I loved: Bleeding Cool suggests that it is Amy and Rory's child but pulled a Daniel-from-the-Sandman in having been conceived aboard the TARDIS.)