@Karlos
Video elements can actually be embedded in canvas, which means they can be transformed at will (for instance rotation, see
http://people.freedesktop.org/~company/stuff/video-demo.html for fun), and there are of course players that add transparent controls over the video area (like vimeo). All this indeed makes it tricky for a simple rectangular overlay surface. That said, there are some other "fast composition" paths in webkit in mac and chromium implementations, but it needs much more work and i'm certainly not there yet. So let's say this fullwindow mode is a bonus.
