First of all. I ain't no huge Batman fan or Marvel or DC Comic fan but let's think about this logically. The new movie with Batman isn't ONLY with Batman. It's MAINLY about Superman. But if the movie is supposedly "bad", it would be ridiculous if fans blamed Affleck.
He's not carrying the whole movie. Superman has to carry the movie.
And there's so many people who have to support the movie. He won't direct it, write it, starred in, produced, craft it etc... Point is. Ben Affleck will do FINE. Rant done.

I fwcking cant wait to see Supes and Bats on the big screen together for the first time! It's a shame the movie got pushed back to 2016 though. Batfleck also has my full support and I'm sure he'll do a great job.