Here's how the Justice League #1 begins as Geoff Johns has told us, but hey pretty art:
Is anyone else reminded of All Star Batman and Robin when they see this? I can't be the only one, but yeah Johns said the comic begins with Hal Jordan asking what are Batman's powers and whatnot.

Then in #2 they meet Superman and we know from Johns that Green Lantern will check out Superman as he's the sector's guardian and Superman is an alien, but honestly how can that ever end up in a "fight" i mean in a DC world it would go like this:
Batman & GL: So who are you really Superman?
Superman: A friend.
Batman: Okay theres this ancient evil menace, can you help us?
Superman: Absolutely, friend.
Batman: Wonderf.... *Batman gets possessed by the curse of Batfans*
Batman: I'm the god damn Batman, blaaa blaa blaa whaa wha my paaaareeeeeeeeeeeeeeents
*Batman jumps at Superman*
Superman: Ah you so cute when you're mad, oh yes you are!
Really i can't see any bigger pay offs with this unless Johns wants to show how paranoid Batman became the best friends with every Leaguer Batman in the 2nd arc.