I'm still inclined to not believe the rumors, but a Boba Fett movie makes almost too much sense. He's one of the series's most popular characters, yet has never been given a real spotlight in any of the films. It's bound to happen at some point.
I doubt they'd do an origin story because there's no reason to. I don't see why Boba can't just be Boba at the start of the film and then do his Boba thing for the film's duration.