I still think Superman and Batman shouldn't be in it. If they're there they'll hog the spotlight and make it even harder to properly establish the others in the space of one movie. They can join up in later installments.
If they want to establish the lesser-known, or at least less-understood, characters without solo movies then they should make it like Mark Waid's JLA: Year One and leave Superman and Batman out of the team's origin (Wonder Woman can stay). It'll stop them hogging the spotlight as they inevitably will. Oh, but I'd have Hawkgirl rather than Black Canary in the line-up, to appeal to the DCAU crowd (and she seems easier to sell to the masses than a woman in fishnet stockings who screams at you).
@Mezmero: Yes, she would be very empathetic having won a murder game, yes? No.
@RalfvdH: Link, please?
People, stop fighting over who should or shouldn't die. If you don't want to see a favourite of yours killed by Hopeless then other people who don't want their favourites killed either are your allies, not enemies. The only thing that needs to die is the book.