Question:
What are your thoughts on cryogenic preservation and the idea of medically treating aging?
His response:
A marvelous way to just convince people to give you money. Offer to freeze them for later. I'd have more confidence if we had previously managed to pull this off with other mammals. Until then I see it as a waste of money. I'd rather enjoy the money, and then be buried, offering my body back to the flora and fauna of which I have dined my whole life.
Note that cryonics is pretty incidental to rationality. If anything, having people live forever is likely to slow down the progress due to increased odds of gerontocracy, and thus be detrimental to the survival of the human species. EY reflects on this in his "3 worlds collide" story.