I'll continue to doubt the practicality of cryonics until they freeze a rat and restore it 5 years later to a state where they can tell that it remembers stimuli it was taught before freezing. If that state is a virtual rat running on silicon, that will be interesting too.
...and this is a weakly continualist concern that patternists should also agree with even if they disagree with the strong form ("a copy forked off from me is no longer me from that point forward and destroying the original doesn't solve this problem").
But this weak continualism is enough to throw some cold water on declaring premature victory in cryonic revival: the lives of humans have worth not only to others but to themselves, and just how close exactly is "close enough" and how to tell the difference are very central to whether lives are being saved or taken away.
In June 2012, Robin Hanson wrote a post promoting plastination as a superior to cryopreservation as an approach to preserving people for later uploading. His post included a paragraph which said:
This left me with the impression that the chances of the average cryopreserved person today of being later revived aren't great, even when you conditionalize on no existential catastrophe. More recently, I did a systematic read-through of the sequences for the first time (about a month 1/2 ago), and Eliezer's post You Only Live Twice convinced me to finally sign up for cryonics for three reasons:
I don't find that terribly encouraging. So now I'm back to being pessimistic about current cryopreservation techniques (though I'm still signing up for cryonics because the cost is low enough even given my current estimate of my chances). But I'd very much be curious to know if anyone knows what, say, Nick Bostrom or Anders Sandberg think about the issue. Anyone?
Edit: I'm aware of estimates given by LessWrong folks in the census of the chances of revival, but I don't know how much of that is people taking things like existential risk into account. There are lots of different ways you could arrive at a ~10% chance of revival overall:
is one way. But:
is a very similar conclusion from very different premises. Gwern has more on this sort of reasoning in Plastination versus cryonics, but I don't know who most of the people he links to are so I'm not sure whether to trust them. He does link to a breakdown of probabilities by Robin, but I don't fully understand the way Robin is breaking the issue down.