For all those who want a black Doctor so badly, I just don't see Moffat throwing continuity out the window.
The Doctor can be tall or short; thin or portly; old or young; white-haired, black-haired, brown-haired, or blond-haired. I really don't think there's a continuity problem with him changing his skin color.
And the ginger thing is a gag they've used twice. Hardly the same thing as an important piece of continuity or foreshadowing.