No Language Lower Than Managed C++
One tenet of the philosophy used in Managed C++ is that there should be "no language lower than C++," not even IL. That, it should be unnecessary to write IL, because every CLR feature available to IL is expressible in C++.
Some examples of this are the additional accessibility modifiers C++ (to represent internal or protected) has over C#, support for multiple indexed properties, and the ability to redefine the raise event.
However, I doubt managed C++ will change certain assumptions of C++, since it would require a new syntax. I thought of these two example, where IL would still be lower than managed C++:
Constructors probably will not be able to call their base constructors in an order different from the traditional C++ convertion. Enums probably will not support custom methods and custom operators; something that I believe can be done in IL.