I was thinking about this recently.
RDF isn't restricted to XML resources. You can make statements about any
addressable (with an URI) thing; HTML docs, GIFs, etc...
Given that the jury's still out on how much XML content there'll ever be, I
think it's safe to say that your statement above may well end up being
wrong. We might also discover that the world is full of busy-bodies
wanting to give us their 2 cents on every topic under the sun.
MB
-- Mark Baker. CTO, Beduin Communications Corp Ottawa, Ontario, CANADA http://www.beduin.com