Thank you for your reply! To be clear, though, I am not wanting to load a kml from a local machine/client to the silverlight app/host/server. Rather, I would like the host map data to come from a kml file on the server (with no user interaction). This can be done with Javascript, I believe. Am I still barking up the wrong tree?
Another way to clarify is that I do not have the capability to serve out my own data as a service. Therefore I must find a way to host my data in another form (perhaps similar to a Graphics Layer stored with the Silverlight Assets?). If this is not viable, maybe Silverlight is not the way to go for me. I do see that others on this list have asked about ways to host kmls and shapefiles directly in their maps.