I ask this all just because of curiosity, but I really hope it does not come across as racist as that is not my intent.
Are there any good black actors who would fit the role? I guess with the recent reports of Doctor Who being racist, they could hit the issue dead on, but it would also be good to branch out and go with someone that doesn't fit the Doctor middle-aged white persona. I know this is such a slippery topic though because it might come across as casting a black guy (or girl) for the legendary role as some sort of statement, but I hope that won't be the case. I just think right now if they really wanted to, they have the opportunity to be different and surprising. It is a risk worth taking.