Justice League #2: Jim Lee Reveals Double Page Spread Spoiler
I suppose it is not that much of a spoiler, but having already read Justice League #1, and seeing these pages are listed as #2 and #3, well...
I think it was already stated that Superman and Batman get it on in this issue.
However, the question you might want to ask is: Where is GL? :)
DCU The Source revealed the following: