I don't see XHTML as being that drastic a departure from HTML that it needs to be separate. Right now, the current state of affairs has us treating most XHTML as stricter HTML. Perhaps as the semantic web picks up people will come up with other, better things to do with it and XHTML might a base for real, non-HTML-like activities. You said "does CPAN need an XHTML rootlevel namespace, or is XHTML simple a subet of HTML." I want to turn that statement on its head and see what the stress points are between XHTML and HTML and see if that leads us anywhere.