Custom Taxonomies and Displaying Archives

Hopefully this will make sense.

I have custom post type Review and a hierarchical custom taxonomy called Reviews which is basically like their category.

So a specific review category shows the correct reviews - ie, http://www.nateshivar.com/reviews/books/

But how do I get the top level custom taxonomy to show all the posts in a similar manner - such as http://www.nateshivar.com/reviews/ which would show everything from all the categories?