I would like to see an ability to build Windows Runtime components that can be used from any supported language using the existing Objective-C code. This would make possible for Objective-C devs spending as little effort building Windows Runtime components using the existing code as possible.

For now, there is only info on how to use Windows Runtime APIs from Objective-C code, but there is nothing I can find regarding how Objective-C code can be used from C++/CX. Building Windows Runtime components could be achieved in two ways: building the ability to create WinRT components into Objective-C compiler and linker, and/or enabling interoperability between C++/CX and Obj-C code so WinRT components could be built using C++/CX that imports Obj-C functions.

Also consider the ability to use custom WinRT components written in any WinRT language (C++, C#, etc.) from Objective-C code.