Fifty Shades Of Grey Movie Being Cast?

I keep hearing the rumor that this movie is in the process of being made and I get excited and then hear nothing else for awhile. I'll be the first to tell you, after having read all 3 books, I'm anxious to see who will be cast as both Christian and Anastasia. Well these three actresses (l to r): Mila Kunis, Ashley Greene and Krysten Ritter are names that have been thrown out for the lead role. If you are a Fifty Shades of Grey fan like myself, who do you think would be the perfect Anastasia out of these ladies, or do you have someone else in mind?