The Web Client Software Factory is released
The Patterns and Practices group have just finished and shipped the Web Client Software Factory. If you haven't looked into software factories before this is a great place to get started, and even if you don't use it in your daily work just studying it will be a great experience.
This software factory make good use of several design pattern. Among the more interesting to be aware of are the View-Presenter and the Service Locator. If nothing else learning these will improve your software design skills
And they have incorporated Windows Workflow Foundation as a possible engine for page navigation. Just take a look at the PageFlow or the PageFlowWithShoppingCart samples to see how it is done.
One negative note though, this Software Factory only generates C#