Who the hell is Lucy Punch and what is she doing in Nicole Kidman's part?

Woody Allen had cast Nicole Kidman to play a high-priced call girl (a role, as I understand it, patterned after Ashley Dupre -- you know, the one that led to the resignation of New York Gov. Eliot Spitzer). Allen's still untitled movie is filming in London with a cast that includes Josh Brolin, Anthony Hopkins, Antonio Banderas, Naomi Watts and Freida Pinto. Problems turned up however when Ms. Kidman realized the film The Rabbit Hole, which she is producing as well as starring in, was going to take up more of her time than she originally thought. So Allen, according to Variety, has replaced Ms. Kidman with Lucy Punch (pictured here).

Now everyone with even the slightest movie I.Q. has heard of Nicole Kidman. but Lucy Punch? OK, that great resource, Wikipedia, informs me that Ms. Punch is "an award-winning English actress" known for (but not by me) her roles in a pair of television shows, Doc Martin and The Class (admittedly, I have seen neither). The award she won was best actress at the Monaco Inernational Film Fesitval for her performance in another movie I have never heard of, Are You Ready for Love.

(By the way, does anyone else think that Ms. Punch, in the picture here, bears more than just a slight resemblance to one Scarlett Johansson, who has appeared in quite a few Allen films of late?)