Sony has released a couple of Japanese PlayStation Vita commercials, one for Persona 4 (which can be found via the link at the bottom) and one for Metal Gear Solid HD. They start out with a general PS Vita promotional montage, showing off its functions and a few games. The actual game commercial starts at the 15 seconds mark. The Metal Gear Solid HD Commercial can be viewed below:
It shows some footage of both games and some of the touch screen controls, such as peeking around corners, using the binoculars and zooming in during cutscenes. At the end it shows the Japanese boxart and release date.