Yeah, the Radio Times have mentioned Pearl Mackie in what appears to be a pretty speculative article. Interesting that she's appeared out of nowhere though! And the idea bandied about that it's a big name...well, that's speculative too, of course. Still, around about this time tomorrow there'll be something meaty to discuss, anyway. If it's really left field, will we see the "Nooo!! Catherine flipping Tate?! Arghhhh!! Doooomed!!" sort of reaction I've heard happened on DS?
(the same RT article states that Cappers (as nobody else calls him) has already started filming the Christmas Special. Really??)