My heart is with Batman but my head is with Superman. 

It pains me to say it but logically Superman would win.  Superman is a Nancy boy parading around in a blue stocking.  I don't like him and I love Batman so this is hard for me to say but if we buy into their powers then Superman would win.

The thing is that whoever had to work on this script had a huge challenge they had to figure out how to make an unfair and unreasonable fight fair and reasonable.

The fact is these two, if they existed would naturally gravitate towards each other in a positive way.  They have a burden no one else could fathom.  They would want to talk to each other and help the other guy.  That's why creating conflict between the two that have worked together in countless ways for SO, SO many years is nearly impossible but we will see.

The issue of Man v. God was the only other big problem but it seems from the trailer that they handled it the only way you could which is to straight up say it's a man v. a GOD.

Dig this...the official trailer came out at Comic-Con over the weekend.