This game has finally been released: no idea whether it will be any good, but it includes the ability to produce movies inside the game and output them to video files (though limited to sticking together scenes from a large library, with your choice of in-game characters, sets and props). Some of the demo videos I've seen during the development looked interesting.

http://www.gamespot.com/pc/strategy/movies/review.html?sid=6139475

However, from the screenshots it does seem to be somewhat biased towards zombie movies :).