Himalia - Model Driven UIs
Himalia looks very very interesting. It's built with Visual Studio DSL tools. It lets you model a UI based on Use Cases, Navigation Models and Presentation Models.
They have an implementation that runs the models on top of WPF but the models are not platform dependent, so they plan to have ASP.NET/WinForms ones.
I'm not aware that there is any similar tool for any platform in the market today.
You can see a 'Pet Shop' demo here http://www.himalia.net/cases.html.