Michael Chabon, writer of Wonder Boys and The Amazing Adventures of Kavalier and Clay, has updated his blog with some fine information about the latter novel's film adaptation, including the casting of at least one part:
Miss Natalie Portman is a strong likelihood for the part of Rosa; other casting is ongoing, as are work on the script (a lot of cutting) and tests conducted by a number of top-drawer animation studios (for the comic book elements). Quick answers (as of this date): Golem: yes. Antarctica: yes. Gay love story: yes. Ruins of World's Fair: no. Long Island: no. Orson Welles: no. Salvador Dali: yes. Loving reference to Betty and Veronica: no. Stan Lee: no.
The Pulitzer Prize winning novel is amazing, so I'm hoping this film version will turn out at least as well as Wonder Boys. Until this shows up in other source more definitive than a blog, I'm going to take this one as rumor. After all, my blog (diary) has been calling Natalie Portman a strong contender as a sexual partner for several years and that still isn't happening. Though, flipping through its pages, my prediction that I'd "feel uncomfortable taking my shirt off in public or private settings" has proved itself true time and time again.