So what do I think? I was sold by THIS compilation of moments from the parliamentary comedy The Thick of It. I figure his Doctor won't be dropping as many F-bombs (yeah, not safe for work without headphones, kids), but do watch for the time travel reference 2-3 minutes in. I like his manic energy, and would love an impatient, grouchy Doctor. Who fans on this side of the Pond probably only know him for his Who-centric work though, though I'm not sure his Roman dad from The Fires of Pompeii, or Frobisher from Torchwood: Children of Earth herald any kind of Doctorish performance.
The look: Who knows what he'll wear, but Capaldi kinda looks like an older David Tennant, doesn't he? (Also, like an older version of my role-player incarnating our Time Lord right now.)
Clue that it was going to be him all along (conspiracy theory edition): He's credited in World War Z as "W.H.O. Doctor".
Clue that it was going to be him all along (BBC $$$ edition): All four seasons of The Thick of It are available in Region 1 from Amazon starting this Tuesday.
So International Geek Week is off to a good start! I'll try to do it proud on the Blog of Geekery, so I hope you'll come back for more Who, plus comics, RPGs and more.