Wasn't there a thing going round a while back about him playing the Master? I'd rather never see the Master again after the crappiness of his last appearance, but if he does come back this would be an interesting casting choice. I've only ever seen him in Sherlock, I have no idea if he's ever played a villain, but I get the feeling he'd be good at it. The Doctor Who and Sherlock fandoms seem to cross over quite a lot though, I guess the fans would find it weird that the same actor was playing the main role in both series. Although, considering the fact that he keeps stressing 'AN episode', I wouldn't be surprised if he has/will have a role in a two-parter or something.
While I'm here, I may as well say this; I'm kind of worried about Doctor Who right now. Series 6 onwards just makes me think that Moffat has stopped caring. The two main responses from the fans are both really, really bad for the series. Either they think it sucks, which is obviously bad, or they think it's the best thing ever. I know someone whose favourite episode ever is Asylum of the Daleks, which just hurts my soul. Rating it so highly when it's so obviously shite just tells the writers that they can get away with subpar effort. I really don't care where they're going to go with Clara because they'll just fuck it up anyway. I really hope I'm proven wrong.
Dat 50th anniversary better be good.