That's according to SuperHeroHype. Not especially surprising, I guess: I'm not sure quite where that series could go now that it seems clear there won't be an X-Men 4. I just hope to god that Fassbender's back as Magneto. The only info they have is a writer, though, so who knows.
SuperHeroHype has learned that Simon Kinberg is writing the sequel to 20th Century Fox's X-Men: First Class, which has earned over $350 million since opening in theaters this June.
Kinberg produced the first film and was a writer on X-Men: The Last Stand. His other writing credits include Mr. & Mrs Smith, Jumper, Sherlock Holmes and the upcoming This Means War and Abraham Lincoln: Vampire Hunter. He is a producer on the latter two as well and is a producer on Neill Blomkamp's next, Elysium.