Game looks really good, I like Batman's juggle combos a lot, looks really fun.
Harley will probably be on my line up of characters: Hammer, gun, bombs, cartwheel= <3. I like her win pose(not sure if it is) and taunts so far too.
I'm really interested in seeing how they handled the Flash, it looked like he had some attack where he jumped into the air and brought his fist down.
Superman's five to start his theatric super move looks like a thunderdive.