This was cross-posted in another message, and I thought it deserved its own thread.

Xamlon (www.xamlon.com) has relased software that allows you to create XAML (Microsoft's declarative UI language) apps today in a .Net environment.

Looks very nice. Theoretically the apps you develop using this will work on Avalon when it finally comes out. Has a cool plugin for Visual Studio that lets you interactively build XAML aps.

One downside is that client machines have to have the .net software on the client machine.