Empire were interviewing Sir Michael Caine and he said that he and the rest of the cast were due to receive their copies of the script in January 2011, start filming in May and aim to wrap principal photography around November.
That makes for a six month shooting schedule, which is pretty hefty, even for a project as heavyweight as this one clearly will be. Nolan will be shooting most of the film in the larger IMAX format, but will thankfully eschew 3D entirely.
More on casting as news develops.