The Tumblrs are alight with much rage about it being another white male, and Moffat and Gaiman's perceived dismissal of same. And yes, that is a disappointment, if not an unexpected one.
But I am interested to see this. Capaldi's Doctor is going to be a very different experience to relate to, I think, close to Ecclestone than Smith or Tennant; the usual route-one zaniness of the Doctor comes off very differently in an older actor than a younger one, and the sense of darkness will be easier to access.
Perhaps because of Malcolm Tucker (okay, entirely because of) I'm finding it easy to picture Capaldi in the Doctor's louder moments, his extremes of emotion and behaviour; it'll be interesting to see how he does the Doctor's quieter, more contemplative/brooding aspects.