What's the difference between C++/CLI and C++/CX?

Lately I've been hearing things about C++/CX. The syntax is very similar to C++/CLI (using ^ for managed 'handles', 'ref class' and 'value struct', etc.), but they added some "C#"-ish keywords as well ('partial', 'sealed').

From what I understand, C++/CX uses the (new?) WinRT rather than the .NET framework, in contrast to C++/CLI.

Can I develop normal programs with C++/CX like I can with C++/CLI? Do they have to be Metro-styled apps, or Windows Store apps only? Does C++/CX require the end users to install the WinRT runtime if they don't have it (like .NET programs require)? Is C++/CX compiled to native code, or does it require a JIT compiler like .NET/Java?

Thanks for your help.