Personally, I think it's a Movie/Theater Mode, where you can "act" out a thing (just normal gameplay) and record that, then go back after and change camera angles and things like that, then save it as a video file onto the hard drive, to be transferred to my computer to be edited. Of course I'm probably just fooling myself, but an example of it might be the new trailer they've put up, "A Day in the Life of a Sackboy" (below) which perhaps is made with this new feature? I'm probably totally wrong, but that would be pretty cool.
http://www.youtube.com/watch?v=lXdEW8q0I2k
