Mmmm, possibly, but it seems to me like a bit of a stretch. And certainly in the past people who've known him very well haven't instantly recognised him in another skin - Sarah Jane being one recent example.
Although I believe it would be different for another Time Lord. Then again, that doesn't work because he'd have recognised her too.

Swarm In A Suit - up to then one of the things impressing me was that this episode had no merchandisable toy. But I forgive them, for it was a bloody good image nonetheless. And yes, I imagine this one will be even better for giving the tinies nightmares than 'Blink'.