Josh Schwartz, the creator of Gossip Girl and The O.C., is in negotiations to write an X-Men spin-off X-Men: First Class says the trades.
This First Class will focus on a younger set of super-powered mutants than the first trilogy, likely focusing on some of the students attending the mutant school introduced in the X-Men movies, like the New Mutants or X-Force.
There's also the possibility, though less likely, that it could serve as a prequel - focusing on teen versions of the current film characters such as Cyclops and Storm.
Marvel Comics ran a short-lived comics series with the same name several years ago.
Producer Lauren Shuler Donner and X-Men: The Last Stand scribe Simon Kinberg are also involved. Schwartz apparently has the option to direct but so far hasn't signed up for the possibility.