Philosophers can argue until they're blue in the face, and scientists can uncover all the evidence they want, but they can never completely convince us that the body and the brain are machines. The final proof will come only when engineers manage to construct machines that are just as complex and miraculous.
This statement may be interpreted as
We shouldn't update until we see this final proof - bad thinking
A large number of people ("us") won't update until they see this final proof - probably a true statement
My impression was that he was leaning on the first more than the second, but on second thought that may just be me being uncharitable.
Sebastian Seung's new book Connectome: How the Brain's Wiring Makes Us Who We Are is very well-written, and aimed at a broad audience.
The penultimate chapter explains why cryonics might make sense given our current understanding of the brain.
The final chapter does the same for mind uploading.
Transhumanism continues its march into the mainstream.
Despite its flaws, I recommend the book.