I have experimented with XAML UI programming using C++ for Windows 8 Store apps. I really like the developer experience, the XAML designer and the fact that I can get pure native apps with a modern rich user interface and high performance.
I want to create similar XAML apps using C++ for Desktop Windows (the non-Store world). How do I do this? For years I have waited for a native UI stack for Windows Desktop which is newer than MFC and somewhat higher level than direct Win32/GDI programming.
Both Silverlight and WPF use XAML along with code-behind to implement apps. Neither are still maintained but if you want to play with the same technology, it’s there.
As Jeff McClintock mentioned, Microsoft has announced that a future update to Windows 8 will allow apps to run on the desktop, but I expect that this will merely be a windowing change and the apps will still run in the restricted sandbox that Store Apps run within. Maybe Microsoft will introduce yet another desktop-based UI framework and support it for three years before killing it.
WTL is newer than MFC, although its last update was six years ago. I personally recommend Qt, as it allows access to native Win32 calls (so you can do whatever ganky stuff Win32 apps normally want to do) while still having a rich, robust UI framework to build upon.
A future update to Windows 8.1 will allow Windows 8 Store Apps to run in a Window on the Desktop, and appear on the taskbar like a Win32 Application. This allows Store apps to Act a lot like Desktop Apps. MS have hinted store-app XMAL will be available to Desktop apps at some point in future.
Codejock has some markup language support in MFC (native C++).