Who should play Daisy in the new Great Gatsby?

Baz Luhrmann (director of Moulin Rouge and Australia) will next tackle F. Scott Fitzgerald's beloved classic The Great Gatsby. 

Luhrmann is reportedly seeking an actress to play Daisy Buchanan, Gatsby's great unrequited love and the type of girl a man would design his entire life around.  After reading message board comments, I assembled the following shortlist of possible actresses that users seemed most excited about -- by no means official!

(Please leave a comment suggesting someone else if you have any brilliant casting ideas.)