I think Peter Capaldi a very good choice to play an older Doctor... something which, I think, is rather apt... to counter balance the youthfullness of Matt Smith, and even David Tennant preceeding him... and also, in a way, as a nod to the original Doctor portrayed by William Hartnell... in the 50th anniversary year.

Will be interesting to see how John Hurt fits into the equation too, of course...

Looking forward to seeing the 12th Doctor in action... and where it goes from here :)

Also really looking forward to seeing David Bradley play Hartnell in An Adventure in Space and Time...