Geoff Johns talked to Newsarama and had some interesting comments about Legion of 3 Worlds:
GJ: George and I want to deliver a mini-series that's epic and character-redefining. But while it's very large in scope, the set-up for the story's straight-forward. It's Superman and the Legion of Super-Heroes versus Superboy-Prime and the Legion of Super-Villains in the 31st Century. And then, like Brainiac 5 of the Legion says, “If this is a Superboy from a parallel world, we need to fight fire with fire.”
NRAMA: So to combat Superboy-Prime, the Legion brings in two other Legions from other Earths, right?
GJ: Yes. The Zero Hour Legion and the current Legion as written by Jim Shooter. It’s a bit of a celebration.
But the central focus of Legion of 3 Worlds is: What is the Legion's role in the universe? Because right now, you come in to see the Legion, and they are told by the United Planets they're useless now. That they don't matter. And as a lot of their members are scattered across the universe, thanks to their recent reintroduction in Action Comics, they're suddenly faced with the greatest threat they've ever come up against while their team is a wreck.
... It's not about rewriting history. DC has done enough of that. It's about building characters back up. From Cosmic Boy to XS.
And I’ve worked extremely hard to make this the most accessible book possible given the arena we’re working in.
...George Perez is a master storyteller. He knows these characters really, really well. He puts in so much work. I can't wait to see someone do annotations on the first issue. If you're a DC Universe fan at all, you'll be in heaven.
...For people who have been reading DC for awhile, we've got that Lightning Rod that Brainiac 5 has floating around. And that will definitely be explored. That's an important piece of the book. And Green Lantern fans will find some interesting things in there as well.
NRAMA: And finally, you said earlier that you're not resetting continuity. But you're going to address why there are three Legions and how they fit together?
GJ: Sure, this about who the Legion of Super-Heroes are, and what the next step is for the Legion -- and someone else important to the DCU. And what the future of the DC Universe is, both in the 31st Century and the 21st Century. A lot of this ties into what's going on now. Of course there will be issues that will deal with the different Legions when they show up. We'll address all of that. We'll address everything we can. But at the same time, the purpose is telling a clear, kick ass, Crisis-style story with me and Perez at the helm and Scott Koblish tearing it up on inks. I hope people give us a try.