Nice blog post (a little long, but worth the read) on adopting Silverlight today, including integrating with back-end web services:
A very common deployment scenario for Silverlight 1.1 Applications is to be hosted from Windows Server 2003/IIS6 environments. This implies that the development environment for Silverlight will be based in .Net Framework 3.5 while the deployment environment will be based in .Net Framework 2.0. Combine the platform mismatch between development and production environments with the fact that we are working with as yet unsupported products and technology and we have a recipe for a failed project. We would be introducing risk into our project. That risk that must be understood and mitigated for if we plan on being early adopters of this breakthrough technology. This article delves into the areas of risk associated with developing Silverlight 1.1 applications that invoke Web Services and that are then deployed into Windows Server 2003/IIS6 environments.
Read the whole thing.