So this rumor just sprang up on Collider, who supposedly have a pretty good track record with this kind of thing:
Is Matthew Vaughn in Talks to Direct STAR WARS: EPISODE VII?
Their sources are positing that the reason Matthew Vaughan abruptly jumped ship from the sequel to X-Men First Class....... was for Star Wars and he's currently in talks now.
I hope it's true, he was one of my top choices! The combination of Stardust and X-Men First Class has me convinced he could do a great Star Wars film. He has great genre sensibilities, his main characters tend to be well developed, his style is dynamic without being a specific "type" of movie each time, and I think he can effectively move back and forth between a sense of fun adventure and mythic seriousness. I did enjoy Kick-Ass but I'm not using that as evidence, I'm looking more at Stardust and X-Men: FC. In other words... pleasebetruepleasebetruepleasebetrue!!!!!!!
edit: Tbaio beat me to it. I do kind of see that it's possible the rumor sprang out of speculation as to why he left X-Men. Still hoping it's true.