When a user alters content they can preview how it will look. This is normally done with the virtual server. In our case the content being created and managed in Alfresco is transformed into HTML for a .Net website. When a user updates content in Alfresco we want them to be able to preview how it will look in the .Net website.
In that scenario, I believe the only option you have for previewing a .Net web app would be to use the FSR (http://wiki.alfresco.com/wiki/FSR). You'd have to setup your own staging environment and deploy to that server. The virtual server is a Tomcat server and can't do much for you .Net app.