I would actually bet money on it that the movie will begin with a scene with Bruce winessing Zod's message in the batcave. He is in detective mode and all of a sudden the lights go out and the batcomputer is hijacked by Zod. "You are not alone." After that, maybe his reactions on the big battle in Metropolis, which will be THE main reason he will go after Supes in the beginning and come to Metropolis. At least, I hope they begin with that, or at least show a flashback later on. It would be bad not to show Bruces reaction.