The Patterns and Practices group from Microsoft released a Composite Application Guidance for WPF and Silverlight (formerly code-named "Prism"). The good news for VB lovers is that they also released VB versions of the QuickStarts, Hands-On Labs, and How-to Topics!
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=537da1cd-43e1-4799-88e7-a1da9166fb46
This download is provided to help the Visual Basic developer use the Composite Application Library. Please note that Prism is not yet 100% VB; however, this is a big step in the right direction. The VB code was written with very high quality, and has been reviewed by VB Language PM Jonathan Aneja as well as VB Doc Writer Doug Rothaus.