So I look at this (Windows build keynote 1:42:56) And I just do not get it - what I can use to cre
If you want to call C++ code the easiest way will be to use C++ with Component Extensions. This is just plain C++ that compiles to native code however it has a few extensions (reminiscent of C++/CLI) that let you use the WinRT COM components without worrying quite so much about the COM plumbing.
With C++ and WinRT you can actually use XAML like the managed languages to define your user interface. It's pretty neat, see the documentation here:
I haven't looked into it but you may still be able to use P/Invoke or COM interop in the managed languages to call C++ code for a Metro style app however this is unconfirmed. Obviously a desktop app can do all the things it normally would.