It looks like there is no support for video and audio at this stage. I tested my silverlight applications on it. All my apps work with both Silverlight 1.x and 2.x, and are written using javascript. I was surprised with the results. All of them worked flawlessly on Linux. Below are the screenshots:

http://ashishware.com/XAMLGraph3DDemo.shtml

http://ashishware.com/SlvrGraphDemo.shtml

http://ashishware.com/Silverlight_example.shtml
Well done ..guys at http://www.mono-project.com/Moonlight !