So it was him after all. Like a lot of fandom I seem to have over-analysed things and ruled him out as a supposed piece of misdirection. But it seems we now have a complete contrast to young, unknown Matt Smith: a well-established 55 year old actor, the same age as Hartnell was in 1963, and arguably the most well-known actor to be cast in the part since Peter Davison.
Personally, I'm excited. I wonder how differently Moffat will write him. And what will happen after his first year in the part, assuming Moffat leaves at the end of Season 34?