Seems like a pretty solid choice to me. I actually like him as Superman. Those movies have other issues, but I've never thought the actors were part of the problem. And he's been good in several other roles.
He's a fan of the games and subsequently the books like many of us here. He almost lost the role for Superman because he was grinding on WoW when he got that call. All this in interviews (check IGN for the witcher part where he says he would love to play Geralt at that time, now we know he has been cast since the past four months)
I still have high hopes for this, should turn out great.