Why She Might Work: The "An Education" Oscar winner would actually be spectacular if they could get her. She's always combined vulnerability with back-against-the-wall edge and if you look at her work in "Drive" or "Never Let Me Go" or "Shame," you could probably come away feeling like this was a part she was born to play. Plus, going back to the "Blink" episode of "Doctor Who" and some earlier British series work, she's comfortable on TV and she isn't necessarily a huge enough star that she'd shy away from the small screen. Certainly if this were HBO, Mulligan would be very gettable.
Why It's a Bad Idea: Mulligan is coming off of playing Daisy Buchanan in "The Great Gatsby" and one could easily imagine her shying from making a career out of reinterpreting Mia Farrow roles. At a certain point, that career path becomes a dead end unless you become Woody Allen's muse.