Why is std::u16cout missing?

C++03 defines two character types: char and wchar_t. (lets ignore the signed char and unsigned char insanity).

These two character are then applied to std::basic_string, std::basic_ostream, etc as std::string/std::wstring and std::ostream/std::wostream.

From the streams the standard library also defines the globals std::cout and std::wcout.

The new c++0x standard defines two more character types char16_t and char32_t. However, the only new typedefs are std::u16string and std::u32string.

Why doesn't the standard supply a std::u16ostream? Or how about a std::u32cout?