I haven't really seen him in anything, so I'll have to stay neutral till I see something. I'm sure he'll do fine though. My partner wasn't impressed, even though he hasn't seen him in anything either. I don't know what he's fretting about really.
One thing that made me smile was doing a search on Wiki to see what he'd done in the past: http://en.wikipedia.org/wiki/Peter_Capaldi
He was cast as a WHO doctor last year in World War Z and it passed us all by!