I remember reading that Microsoft was moving the WPF framework into maintenance mode as they focus on the WinRT variant of UI development. Interesting that from the release notes, WPF appears to be getting feature development again. Hard to know without Windows 10 consumer announcements if Microsoft internally is back-tracking on the idea of fullscreen desktop apps.
Visual Studio itself is a WPF app, for what it's worth. I can't imagine Visual Studio being rewritten as a "Modern" app any time soon. So, it makes sense that MS will continue to invest in WPF.
When no dialogs are open, the overwhelming majority of the UI is WPF now though, to my knowledge. I remember running debug builds of 2010 that showed paint rectangles and there was basically nothing that wasn't WPF even in that first WPF version.
Enterprise backlashed and they had to respond. There is no need to suffer through backwards-compatible legacy stuff (JS, HTML, CSS) if you are not building something public-facing.
