Sometime in the future, science will be able to create realities that we can't even begin to imagine. As we evolve, we'll be able to construct other information systems that correspond to other realities, universes based on logic completely different from ours and not based on space and time.
In fact when you combine stem cell technology with the technology known as tissue engineering you can actually grow up entire organs, so as you suggest that sometime in the future you get in an auto accident and lose your kidney, we'd simply take a few skin cells and grow you up a new kidney. In fact this has already been done.
Space and time, not proteins and neurons, hold the answer to the problem of consciousness. When we consider the nerve impulses entering the brain, we realize that they are not woven together automatically, any more than the information is inside a computer.
For example, if the big bang had been one-part-in-a billion more powerful, it would have rushed out too fast for the galaxies to form and for life to begin.
I do not think that there is a reputable scientist on this planet who would advocate using this technology to generate a human child as was just announced.
Today's preoccupation with physical theories of everything takes a wrong turn from the purpose of science - to question all things relentlessly. Modern physics has become like Swift's kingdom of Laputa, flying absurdly on an island above the earth and indifferent to what is beneath.
We don't have time to wait for President Bush to change his mind. How many breakthroughs have been missed as a result of this policy?
