Batman 3: It’s Official! …Kinda.
There is reason for a premature celebration! Why? Well…
Christian Bale’s filmography (under Killing Pablo and Terminator 5) reveals that an Untitled Batman Project is in the works. But since this is quite early on, and in pre-produciton, this is technically subject to change. For that reason, I would say it’s only semi-official. Further (if any) details are available only to IMDB pro members. If you are one of those lucky few, congratulations! Maybe slip me a few tidbits of info?
On that same subject, it has been rumored that the director, Christopher Nolan, has the ambitious goal to shoot the “potential” third film entirely in IMAX. I wouldn’t doubt it, from how much he praised the technology after filming 30 minutes of The Dark Knight with it. It’s been theorized that he’s also using some of his time working on Inception to develop IMAX rigs customized for future usage. So a full-IMAX-feature is definitly plausible. Nolan did admit to have jotted down notes and a rough outline for a third film, but nothing he’d be willing to commit to on film yet.
So, in short: The third (and final?) film of the rebooted Batman franchise is coming…eventually.
Source: IMDB, Slashfilm

