I think the Microsoft Dev team is a lot more forward thinking these than many give them credit for. A lot has changed about MS development tools in the last 10 years.

The whole thing about "it shouldn't be a web page- it should be standalone"- well that's true in a lot of cases- but often it's difficult to get the decision makers to see this. At least the new XAML technologies allow you to esentially build it either way using the same tools and let the client decide how to deliver it. We are currently building a HUGE line of business Silverlight app and we may end up setting it to run out of browser, so it won't even really be much of a web app in the end. Honestly we probably would have been better off doing it as a client app, but they were dead set on a web app.