How the Client HTTP Stack Works
One of the new features that is of interest is the new Client HTTP stack. By default, all web requests go through the browser’s HTTP stack. This is a good thing because if you’re using depending on the networking calls to come from the same page, it acts this way. For example, if you are using Forms Authentication, then all browser HTTP stack network calls come to the server with the auth cookie that is used to indicate a logged-in user. So from your perspective this is often still the best way to handle networking from Silverlight.
So if the browser stack is still good, what can’t it do?