You know, they keep making changes to this timeline in order for it to be back where they want to be, but I'm wondering. When they went back to the present, they saw themselves. So does this mean they're actually messing with an alternate timeline?

"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