C++/WinRT is now available on GitHub. This is the future of the Modern C++ project and the first public preview coming officially from Microsoft.
https://github.com/microsoft/cppwinrt
C++/WinRT is a standard C++ language projection for the Windows Runtime implemented solely in header files. It allows you to both author and consume Windows Runtime APIs using any standards-compliant C++ compiler. C++/WinRT is designed to provide C++ developers with first-class access to the modern Windows API.
C++/WinRT, along with libraries like Boost and Range-v3, has been instrumental in helping us find bugs in our efforts to make the Visual C++ conform to the C++ standard. C++/WinRT works with the latest Visual C++ compilers including the toolsets in Visual Studio “15” Preview 5 and Visual Studio 2015 Update 3.
Please give us your feedback as we work on the next set of features.