its not my usual type of post "yet another xxx download available". But Expression Blend is available as release candidate. Package is round about 25 MB.
I am trying since a few weeks different things with WPF and XAML. The worst point at the moment are the missing tools. In general this is really a revolution step in UI design. If you come from the ASP.NET web side you will feel familiar with XAML. But there are hugh differences. Eg how to place a element in a grid cell. But try it yourself!