As a clarification I should say that I don't regard the uploading scenario I described as the most likely possibility. I posted it because I think its an interesting way of arguing for the singularity, not because it reflects my best guess about what will happen.
Nick Bostrom
http://www.hedweb.com/nickb n.bostrom@lse.ac.uk
Department of Philosophy, Logic and Scientific Method
London School of Economics