Scott, returning to science fiction with Prometheus after a nearly thirty year break from the genre, briefly spoke to the Wall Street Journal about the progress of this new Blade Runner, commenting that it is "liable to be a sequel.” We knew it wouldn't be a remake, meaning it was either going to be a prequel or a sequel, and Scott seems to be favoring the latter.
As for development of the story, Scott said, “I think I’m close to finding a writer that might be able to help me deliver. We’re quite a long way in, actually.” The director is usually actively involved in developing the stories he directs, meaning he could have a rough idea of where this new Replicant-focused feature might go.
He's also a noted world-builder, paying a whole lot of attention to creating the textured, detailed environments in which his films take place. Perhaps Scott is "quite a long way in" creating the visual look and feel of the new Blade Runner, without having yet hired a screenwriter.
The director also said that the film would proceed, but "not with the past cast, of course.” Asked if that means Rick Deckard won't be back, Scott answered, "“No, not really."
So we know know a teeny, tiny bit more about this altogether surprising project. One thing we've known for sure since Ridley Scott became involved is that it will be a 3D feature. Prometheus, which is scheduled for the summer of 2012, is Scott's first foray and 3D, and he has publicly stated that he'll never again make another movie in conventional 2D.