While the discussion was targeted more at the actual value of software patents (i.e. what specifically Apple 'invented' with their multitouch patents), in actual practice yes such a movie is prior art if the novelty of the patent is the application of multifinger gestures. The idea that you need to show a working implementation is nonsense, and has never been a requirement of the patent system.
Regarding warp drive, the novelty of multitouch is the mere concept of using multifinger gestures on an interface. The novelty of a warp drive is the mechanism of achieving warp drive, not the concept of it.
To put it another way, if you patent a method (or system) of making a car fly, maybe that's an invention. Patenting the concept of flying cars, however, is not.