Composite Application Guidance for WPF and Silverlight v2.0, including the Stock Trader Reference Implementation, is available to download at the MSDN and Codeplex site. 

The Composite Application Guidance for WPF and Silverlight is designed to help you more easily build enterprise-level Windows Presentation Foundation (WPF) client applications. This guidance will help you design and build flexible composite client applications-composite applications use loosely coupled, independently evolvable pieces that work together in the overall application.