I'd really love to see him work his delicate magic on a Bond film, especially now Sam Mendes has really opened up the style with Skyfall. I feel McDonagh is in many respects on a par with Mendes, yet with his own special touch as well. I love In Bruges and think he could certainly handle the higher octane action pieces of a Bond picture very well also.
Oh and if you haven't seen In Bruges give it a watch, it's a a gem - brilliant black comedy drama.