From an Onion A.V. Club interview with Sam Rockwell:
The A.V. Club: So you’re working in London right now?
Sam Rockwell: I’m in jolly old London. I’m working on a science-fiction movie called Moon. And it’s just me and a robot. That’s it, man. You ever seen a movie called Silent Running with Bruce Dern? It’s sort of like that.
AVC: Or Castaway?
SR: It’s a little bit like Castaway, too, except my character is on the moon and he meets his clone. That’s a little different, too.
AVC: So unless the robot is really charismatic, this is obviously a leading role. Does your mindset change when you’re cast in a lead role rather than a supporting role?
SR: There’s a mixed bag with it. It’s more responsibility, but it’s probably easier to do a lead role, because you just get into a groove, vs. a supporting role, you wait around more.
I now know absolutely nothing about this film beyond what you see above — and that I desperately want to see it.