I don't think it would bother me personally to have a black Bond. So long as the character is male. Even some of the sexual ambiguity (which they ever so deftly touched on in Sky Fall) doesn't bother me. Bond is a killer who would **** damn near anyone, men or women, to get what he wants/needs for the mission.
As mentioned above, it seems Aaron Taylor Johnson is the odds on favorite, but if they do go with a black actor, my vote goes to Rege-Jean Page. He's still 37, so young enough to carry the role for a decade plus, and some of his roles show he has an edge and isn't just a pretty face.
I read some people that wanted Damson Idris after F1 came out. He's a damn good actor and I like him a lot but don't think he's Bond.
And as mentioned repeatedly, Idris Elba is too old now. If he was the guy, they should have picked him when they selected Craig instead.