Matt and I travelled up to Birmingham on Monday night to talk Vista, Office and .NET 3.0 to the Next Generation User Group. One of the things I covered was WPF/E and it got attracted alot of interest from the guys.
WPF/E is the little brother of WPF and allows the rendering of XAML directly in the web browser. We're touting WPF/E as cross-browser and cross-platform so to run WPF/E all you need is a browser plugin which at the moment will run on Windows and Mac OS IE, Firefox and Safari.
To get started with WPF/E check out the following links: