A photo taken by Toy Ark at Toy Fair 2012 has curiously placed Activision as being involved with Nickelodeon's new Teenage Mutant Ninja Turtles series. The picture appears to be of a sign detailing a marketing plan; one of its bullet points is "Cross-promotions with key licensees, including IDW & Activision."
While that's the beginning and end of this rumor, it seems entirely plausible that the publisher would work on such a videogame. (It's not going to be THQ, anyway.) TMNT has always meshed well with gaming, even if the notion that this would stem from the Nickelodeon show is less appealing.
I think I'll be okay so long as there's no seaweed-infested water level. I still have nightmares.