Why Brad Pitt? I have nothing against him, keep in mind, but couldn't they find an actor who actually bears a close resemblance to Lennon?
Also, he wants to do the singing himself? The Beatles fan in me is screaming "NO!"
From the looks of it, he seems very dedicated to the role, and is taking voice lessons, so I'll give him a chance. The articles at least mentioned that recordings of Lennon's voice would be used for the singing if Pitt can't pull it off.