Intermediaries and XML Protocol

I've put down some thoughts about intermediaries and their
relationship with XML Protocol. I apologize for the length, but I
haven't had time to make it shorter (as they say).

Feedback/suggestions would be most welcome. At this point, it's
unfinished - it meanders, the terminology probably doesn't match what
we've been using, and the references haven't been added - but I hope
that it might help in the intermediary discussion that's been going
on recently.

Cheers,

-- 
Mark Nottingham, Research Scientist
Akamai Technologies (San Mateo, CA)