The actor David Bateson is the one who borrowed his looks for 47, he also does the 47's voice. It is a shame he didn't get the role.
http://www.imdb.com/name/nm0061055/The actor who plays 47 is Timothy Olyphant, he was the baddie in Die Hard 4 and played a role in The girl next door, seems to have a role also in Deadwood. Surprisingly, he is 39.
http://www.imdb.com/name/nm0648249/However I agree that he doesn't look like 47. I wonder what will be the violence rating of the movie. The trailer has some interesting game like scenes, like the filmatization in the end of the trailer where 47 is pulling the silenced gun.
Hopefully they don't make 47 a hero in this movie, I still don't know what to think of the text in the beginning, I thought it can also be read differently than implying 47 is a hero. Anyways, I will wait for the reviews before going to see it.