I just installed the ASP.NET Futures Release from July in order to get my hands on the new XAML server control.
One interesting note about the installation: the docs imply (and other commenters have noticed) that you need to manually add the MIME types for .xaml and .dll in IIS:
To run ASP.NET Web pages that contain the Media or Xaml controls when using features such as the XamlUrl property, managed code, or dynamic languages, you must set up MIME types in IIS for the following file name extensions: .xaml, .dll (for using managed code assemblies), and .py and .jsx (for using dynamic languages). For more information about how to configure ASP.NET Web sites for using Silverlight controls, see the Readme.htm file in the Silverlight_1.1_Quickstarts.Zip file. This .zip file is part of the Microsoft Silverlight 1.1 Alpha Software Development Kit (SDK) on the Silverlight Web site.
However, running Vista Ultimate with IIS7, I found that after the Futures install I already had those items mapped properly. I can’t say for sure that this install did that, but can’t think why the Silverlight 1.1 SDK would have set those MIME types for me.
Blogged with Flock