Set to start filming in early October
In an interview at the Toronto Film Festival (where Mia Wasikowska has three new films being premiered) when asked what film she was doing next, she said that she would be doing "Madame Bovary", which was to start filming in three weeks.
http://blogs.indiewire.com/theplaylist/interview-mia-wasikowska-talks- working-with-richard-ayoade-jessie-eisenberg-in-the-double-20130910
quote is around 11:00 min into clip.