Last night a noticed a couple of blog posts on MSDN referencing the new WPF/E Developer Center on MSDN. None of the downloads for the SDK or runtimes for various platforms were up, but there was some core content.
Today when I went back to follow up, the Dev Center content was gone! I sound like it will launch soon, but some of the content appears to have snuck out early. If you missed it, it looked something like this: