Director Louis Leterrier has confirmed with ComingSoon that he'll be back to helm the followup, though it sounds like it's still in very early stages. "I'm currently, not writing, but we're coming up with the story, the plot, the everything, the twist and the new characters and everything," he explained. "It was always at least a diptych, two movies, to tell one long story, so yeah, I'm very much involved in it. I don't know if it's going to be my next movie. I know we want to do it pretty fast but I might be able to do another movie in between."
Leterrier also noted that on the forthcoming DVD/Blu-ray release there would be a credits stinger—one that was shot, but kept out of the theatrical cut—that points much more heavily toward a followup. There's also no word if any of the cast—Jesse Eisenberg, Mark Ruffalo, Melanie Laurent, Isla Fisher, Woody Harrelson and Dave Franco—will be back. And while a 2015 release has been tossed around, considering Leterrier is already hinting he might make something else first, this might be a bit further off.