Yeah, that's very mysterious. Or it would be, if this wasn't the usual Hollywood rumor explosion. I wonder who comes up with crap like, "Shia LaBeouf is rumored to play the lead role", when the producer says they haven't even had readings or anything of that sort yet. Uh, gotta love the internet.
Anyway, Spacey says the project is at a very early stage but yet it's being fast-tracked with shooting as early as this year. In all honesty, that doesn't sound too much like a Fincher movie: The first draft of the script is dated May 28, and factoring in some rewriting they would have to be lightning fast. But we'll see...
Here's the source: