I am not sure if this is the first web site that uses JavaFX for production, the official web site of the Vancouver Winter Olympics 2010 is using JavaFX for displaying the medal history of the Winter Olympics Games. In this winter, Vancouver is probably hot for Olympics, so is JavaFX. ( Check it out here: http://www.vancouver2010.com/olympic-medals/geo-view/ )
This is a very cool demo (oh, I should say real world application) of the JavaFX visualization technologies. Overall, it works well except for some animations were not so smooth. Though the same effects can be achieved by Flash, I would say this is a good start for JavaFX going into practical use. Hope to see more and more such applications in JavaFX.