I was recently verbally abused by Hollysince1985 for not informing her that this was going on...however, I had no clue...I don't follow KK's career developments. I have novels to analyze and expository papers to write.
But--imdb.com lists that KK has been cast as Zelda Sayre later Fitzgerald, the mentally unstable wife of celebrated American author F. Scott who coined the term 'the Jazz Age' for the 20s. There is no mention about who will play Fitzgerald.
So, looks like it is another period piece for Knightley...my only question is: Does she plan to put on weight?
As you can see, Zelda had ample rump.