The article I read implied that it was a hero that hasn't been reintroduced yet, which leaves out Supes and the Bat. "Among the contenders, then, are Martian Manhunter, Black Adam, Shazam! (aka Captain Marvel) and Hawkgirl."

"You need me. You wouldn't be much of a hero without a villain. And you do love being the hero, don't you. The cheering children, the swooning women, you love it so much, it's made you my most reliable accomplice." -- Lex Luthor to Superman, Question Authority, Justice League Unlimited