In WPF the XAML was about users creating their own differentiated and customized XAML, but in Windows 8, they have done a lot of the hard work for you, adding a boatload of animations, effects, and styles that you can use. This - effectively - removes the need for designers in 80% of application developers use cases, and since blend is written in WPF, that now is also no longer supported.
????? Are you saying that Blend is no longer supported because Blend is written in WPF? Wouldn't that imply Visual Studio is also not supported, since it's written in WPF too? Not to mention WebMatrix, Powershell ISE, others?