Ewan could do it. Take some of the dark stuff we saw in Trainspotting, the moments of raw intensity combined with utter disconnection from standard morals (Bond has no trouble getting his white hat a bit dirty if it gets the job done), and combine it with the suave self-assurance we (er, I, maybe) saw in Down with Love, and then add enough of the action-scene capability that we've gotten used to in the Star Wars films (sure, a lot of it is CG, but he's shown that he can follow choreographed fight movements well and with emotional sincerity, at least, in my mind), and you've got a pretty darn good Bond.
And my wife, who watched Down with Love with me, was, by all appearances, quite satisfied with Ewan in a tux -- which is, of course, an enormously important prereq for Bond-ism -- or, what should we call it? Bond-age?