Teaser trailer for Terminator 3, Rise of the Machines. When you hear the words teaser trailer, it means that someone takes music from the previous films, whips up something in a digital animation program (usually its a bunch of moving logos or patterns that end up forming the title font for the next film), and releases it to great hype. It is a fancy way of telling people the date when your film will release. In fact, this trailer is almost exactly the same as the X-Men 2 teaser trailer floating around the web.
T3 comes out July 2, 2003, if you really want to know.