Have been working with Silverlight since last month. Its a really cool thing and has lot of potential. Posted an article on the 'CodeProject.com' on creating real time AJAX line graphs with silverlight.
You can read it here : http://www.codeproject.com/silverlight/Silverlight_AJAX_Graph.asp
It can have many applications in Web 2.0 applications. Planning to do more interesting things with Silverlight.