Windows 8 will use Metro UI, even it support xaml.But that is different from WPF.Will Metro UI kill WPF? Around 2008, WPF started to get the market. At that time, I had asked whether WPF will kill Winforms. But now, I am writing some Winform applications. Winform is still alive, that is too early to say whether Metro UI will kill WPF. Moreover, Metro UI sounds a Tablet UI rather than a Desktop UI. So, I still thinks WPF will worth while.