The film, titled "Saving Mr Banks", has a script by Kelly Marcel detailing how Walt Disney spent 14 years coaxing PL Travers, the Australian author of Mary Poppins, in order to adapt her books about the magical nanny.
Travers resisted for so long because she feared Disney would make an animated adaptation. The studio finally made a live-action movie in 1964, starring Julie Andrews and Dick Van Dyke, but stuck in animated sequences, which turned the author off from working with Disney again.
The studio picked up the Black List script earlier this year and later set John Lee Hancock (The Blind Side) to direct. Hanks is currently shooting Captain Phillips, Sony's true-life tale about the captain who dealt with Somali pirates during the hijacking of the Maersk Alabama. Thompson will be seen in this summer's "Men in Black III" and voice a character in Pixar's "Brave".