Chance of leaked footage?

There have been a few high profile movies in the past couple of years that had "leaked footage" online. Wolverine is the only one that comes to mind at the moment. Leaked footage is in parentheses because it's been suspected that the studio actually leaked the footage themselves to drum up buzz about the movie. No doubt if it's a good scene it could help the film. I think Prometheus is a prime candidate for this tactic. I'm gonna call it now and say that it will happen to this film ahead of release. I don't think it would be anything that would spoil it for anyone, just something to whet (I think thats how you spell it) their appetite.