> sys is a very important and often used module, too. I don't like the
> idea to remove one module (types) and clutter an important module with
> its content.

Well, it is already pretty cluttered -- it contains many items that
*I* don't recognize... :-)

> The list of types has grown pretty long and most of the types can't be
> instantiated in Python. I fear that the types are going to confuse too
> many people. However the types are useful for type checking and ABCs.

Stuff in sys that people don't use doesn't really confuse anyone IMO.

I really don't think that this warrants a new module.

Many of the datatype-related types (e.g. dict_keys) should not go
there but in _collections anyway.