Question: For example:

`shared_ptr<const shared_ptr<const int> > pp;`

is fairly intimidating... whereas

`const int ^ const ^ pp;`

is instantly reminiscent of the raw pointer equivalent

`const int * const * pp;`

Answer: 
Probably won't be done, if nothing else because Microsoft already uses `^` in C++/CLI.
Very unlikely. C++ is already an intimidatingly complex languages and adding one more feature with potential ambiguities (XOR operator already used) + the fact that Microsoft's CLI version of C++ uses this syntax for managed references -> chances for it happening are close to zero.