They are going to connect the whole Multiverse together,to bring back characters who died, so lets say Logan died, they will bring him back from a different Earth, (or maybe its too soon for him..), Mostly they want to move Miles to 616. (which happened already but whatever..)
This whole Multiverse thing with Marvel and Dc is so lame, why cant they focus on making good storys instead of messing around with the Multiverse... who cares what happends on the others Earths?!
Hyperion vs Superman, Thor vs Shazam (Thor wins..),Hulk vs Superman (after he beats Hyperion), Ironman vs Lex Luthor, Shang Shi vs Green Arrow & Katana, Sunspot & Cannon vs Cp. Cold & Vibe, Wolverine vs Catwoman ( Logan wins of course..) Captain Universe vs GL & Manhunter, Smasher vs Aquaman, Ex Nihilo vs Wonder Woman, Captain Marvel vs Cyborg, Nightmask and Manifold vs the Flash.
Captain America vs Batman - I'd say niether would win, both getting to a conclution that they are both on the same side and under @micah's control of a Secret War Multiverse Battle, then together stoping the fight on both teams.
Bloodlusted version of Hyperion Thor and Hulk alone can go crazier than the JL... I'd Say Avengers win here.
Captain America, the Avengers are more loyal to him and they do what he says, I'd Say Batman would win but Hal + Lex + Shazam.. to much ego.. they wouldnt listen to him and would try their own way.
I havent read before New 52 so i dont know.. Im guessing same as Round 1.
Adding the most powerfull Cosmic characters to the Avengers Team.. JL dont stand a chance even with the ones you added to them.