Larry, you've wanted to have class names used within a class be
virtual. With various degrees of conviction across the synopses, you've
wanted classes defined within a class to be overridable, or all classes
referenced by a class to be overridable, speculating on whether this is
do-able.
I've worked out all the details, included a specification on pages 66-69
of my document. The excerpt is at
<http://www.dlugosz.com/files/virtual%20class%20names.pdf>, and the
whole document at specdoc.odt and .pdf.
You'll be happy to know that not only is it do-able (once you know what
is and is not affected), but it will play a role in making the type
system F-bounds quantified.
I hope you have a few minutes to look it over.
--John