Singer caught up with THR's Heat Vision to drop the usual "I know what the story is, but I can't tell you" hints, but he did reveal that First Class had essentially absorbed Magneto's spin-off movie. "It's basically about the formation of the X-Men. How they began and the relationship between a young Xavier and a young Magneto ... This story would probably utilize some of the Magneto story because it deals with a young Magneto, so it might supersede that [origin movie] because this would explore that relationship between a young energetic professor and a disenfranchised victim of the Holocaust."
We already knew that X-Men Origins: Magneto had been put on the backburner in favor of Wolverine 2, Deadpool and First Class, so it's not particularly surprising that it might be canned altogether. It's probably for the best. While I'd still like to see a supervillain origin story, and I still think Magneto would be a fun one, I really do hate the assembly line of prequels. There's just so little point to going back and telling fans what they already know about their favorite characters. Fox's superheroes need to move forward, particularly if they ever hope to catch up to Marvel Studios' output. I highly doubt you'll see them go backward and tell the story of James Rhodes' boot camp experience, or how Obidiah Stane came to work for Stark Industries. If they do, well, that's the day I want to see Hollywood close the shutters for good.