This is done through Flash. Each "video" listed is a Flash movie showing a static image, when you move the mouse over it an event handler in the Flash script fires and starts playing a snippet. When it detects a "mouse out" it stops playing the movie.
So you'll need to do something similar. A Flash movie that accepts a URL to an arbitrary movie file some where on the internet. The Flash movie would load a bit of that movie and show the first frame when the movie's been loaded. When a mouse over is detected you play the loaded snippet, and on mouse out you stop playback.
The URL would be something that your search engine provide.
I'm sure you can do the same with Silverlight if that is your preferred toolkit.