I haven't seen the movie and I'm not going to see it. But isn't Batman just a middle aged guy in a Batman suit? What's he going to do to Superman?
Not surprisingly, Batman resorts to using kryptonite. Hell, I could defeat Superman if I had kryptonite. There's no trick to that. It could be absolutely ANYBODY vs. Superman.
Anyway, the movie will have to gross $800 million just to break even. The critics don't care for it. It doesn't look like it's going to lose money and it doesn't affect me in any way, but I hope it fails.