I think Ray uses "upload" as shorthand for something more complex.

Say over the course of 10 years you replaced 1 of the millions of cortical columns in your neocortex every minute or so with a functionally equivalent computer chip. You would never stop being you. Your consciousness would never be interrupted. You would simply become something greater.

This is already happening in a very limited way with the various brain implants used to treat Parkinson's, hearing impairment, blindness, strokes, head injuries, etc.:

http://en.wikipedia.org/wiki/Brain_implant