Craig was from "The Lodger" last year, the one where the Doctor got separated from the TARDIS and had to spend a few days renting Craig's spare room and unsuccessfully pretending to be a normal human being (at least until it turned out that the chap upstairs was an alien with designs on the planet, as tends to happen when the Doctor's around).

"I speak Baby" was done before, more briefly, in "A Good Man Goes to War", when he met baby Melody.

On the whole, I agree it wasn't a terribly good episode, though I think for me it managed to have enough fun bits (mostly involving the Doctor interacting with small children) to avoid being negatively enjoyable.