Interesting Read on Silverlight 2.0 and WPF
Pete Brown has a great blog post here on Silverlight 2.0 and WPF. Pete makes some great points on what Silverlight 2.0 will bring to the table as well as mentioning what is available today with WPF.
As Pete points out, writing applications in WPF does not rule out the web deployment model. While the WPF web deployment model does not allow the same level of access as say an MSI deployed application, web deployed WPF applications do have the same level of access as a pure browser-based application but with the capabilities for a much richer user interface.
The original "Smart Client" deployment model for Windows Forms introduced in .NET Framework 1.0 has been greatly improved with each release of the .NET Framework and Visual Studio. It is worth taking another look at WPF and the available deployment models for Intranet applications or Extranet applications where the client-platform is Windows.
WPF Deployment Resources:
British Library "Turning the Pages" WPF Internet Browser Application
WPF Soup to Nuts Webcast Series
Deploying a WPF Application (MSDN Docs on the subject)
WPF Composite Client (Announcement)