I just read an article about this upcoming movie a few days ago. I think that Audrey is a great choice to play Coco Chanel, given that Audrey kind of resembles a young Coco (and she's French too!). I'm very picky about that type of thing in a biopic -- I hate to see an actor/actress who doesn't really resemble the famous person that they are playing.
And someone here said that they think Audrey is "too young" to play Coco. Well hello, the movie is called "Coco Before Chanel".