I still think the article is being misinterpreted big time. I received this bit of info on February 12th, I believe Moviehole received it on the same day. Then Blockbuster ran the same info days later with other sites to follow. Just pointing that out. Also, just because this is what others and I have "heard" doesn't make it true. It is a rumor, but a very strong rumor. You know what they say about rumors, there is always some truth to them somewhere at their foundation.
The synoposis describes the Justice League trying to move forward without two of it's strongest heroes. However, nothing in the synopsis indicates that Superman and Batman are not featured in the script. The Batman story arc where he is kicked out of the JLA due to the aftermath of Brother Eye is nothing new, we heard this months ago. The Superman storyline involved him going rogue due to some manipulation and fighting Wonder Woman and Batman, now we are hearing he dies in a fight with Doomsday. Nothing suggests to me that these heroes are not in the script.
For some reason some of the websites are misinterpreting this to mean Superman and Batman are not in the movie, which I think is a terrible misconception based on the synopsis.