WPF/E is there, but one thing puzzles me...
The samples of WPF/E look stunning, the kind of effects we are used to see in Flash applications. I had a quick look at the WPF/E SDK, and one thing puzzled me: it looks like WPF/E currently only provides a DOM, and that the Javascript runtime as available in your browser is used to access the WPF/E DOM. This means that you still have to solve all Javascript language differences between different browser platforms. It also means that things like interaction with the server (for example AJAX calls) must be handled through the browser Javascript. If my quick observations are correct it means that for WPF/E we are still dependend on the same cross-browser AJAX solution libraries as we are using for our current AJAX sites; libraries like prototype, , scriptaculous, AJAX .NET Professional, and of course ASP.NET Ajax.
At one side this is great, all knowledge on this technology can be reused and the possibilities are infinite. On the other side: there is not a well defined boundary to do your programming in, where you are sure it works on all platforms. I think this is one of the advantages of a platform like Flash.
On the other hand: in a future release a micro version of the .Net framework will be embedded, maybe this will provide this boundary. In the mean time I forsee all the cross browser problems we all love in our current "old technology" web solutions.