As she does the promotional tour for James Cameron's Avatar, the mighty Sigourney Weaver has managed to drop some interesting bits of information about the upcoming Ghostbusters 3. It's a film that we're guessing will finally go before the cameras in 2010, and Weaver has dropped a few plot points into the mix.

The new information is contained in an interview she did for Channel 4, where she firstly reveals that her son in the films, Oscar, will be a Ghostbuster in the new film. And then she adds something that could prove to be a stroke of genius:

"I might be in it; I see nothing wrong with being in it, although I don't think I will have a big part. I think Bill Murray has a little more to do with it. He's a ghost."

Bill Murray as a ghost? Where can we buy a ticket?

We're still a bit um-ah about a third Ghostbusters films, but there's clearly potential - especially with much of the original cast back - to do something genuinely strong. We expect to be hearing a lot, lot more about the project next year.

Here's the interview at Channel 4.