WinRT, not yet another abstraction over Win32!
Not just an abstraction over Win32 API.
The new developer stack for windows looks like
Any class compiled to target WinRT is called WinRT Component. A WinRT Component written in one language can talk to another WinRT component written in any supported language. This magical intercommunication between WinRT components happens through Language Projections.
Language Projections is the another word for Bindings in WinRT through which Windows Runtime APIs are exposed in each language. As show in the image, Language projection utilises Metadata exposed by each WinRT component.