> And it's resulting in a huge blank file.  Oh well.  Does 
> anyone know what I'm missing here to get this to work?  Also, 
> I'm not really handling namespaces here, i.e., the elements 
> are actually called xs:import, xs:simpleType, etc.  

You've answered your own question. Since the elements are actually called
xs:import, xs:simpleType, etc, trying to refer to them as import and
simpleType isn't going to work.

Refer to them as xs:import, etc, and declare the xs namespace in your
stylesheet.

Michael Kay
http://www.saxonica.com/