Really? They picked an established actor this time? And an older one, as well? Colour me thunderstruck that it's Peter Capaldi.
Otherwise, I have no opinion on the matter. I've only ever seen him in 'Fires of Pompeii', the 10th Doctor & Donna episode from S4 so I've no idea what sort of actor he is. Though I have a suspicion he won't last long in the role, because it really is a young man's* game...
*I say "man" advisedly, because despite Moffat's comments, I cannot see them ever making the Doctor a woman.
Beware spoilers in the comments.