I can’t believe that Badiou is serious (I feel the same way about his philosophical writings). Nevertheless, I hope that he succeeds. The Platonic dialogues were often performed as dinnertime entertainment in the Hellenistic period. Although it might not please scholars, there’s historical precedent for a film. 
But I have quibbles about Badiou’s dream cast, which would include Brad Pitt as Plato and Sean Connery as Socrates. For one thing, Plato doesn’t appear in any of the dialogues. So Pitt would presumably be limited to a silent role. He might have more opportunity to display his talents as Alcibiades.
More seriously, Sean Connery, is much too good looking to play a man whose bulging eyes and pug nose were the object of mockery to his contemporaries. How about Wallace Shawn? Or Paul Giamatti? 
Apart from the stars, a film about Socrates would offer wonderful roles to character actors. Who would play the loyal Crito? The dim Euthyphron? The spirited Thrasymachus? Are there any figure from the dialogues you’d particularly like to see on screen? Personally, I’d love to see a cameo appearance by Aristophanes, who was the first to see the crowd-pleasing potential in all this nonsense about philosophy.