(My version of) the above is essentially my reason for thinking cryonics is unlikely to have much value.
There's a slightly subtle point in this area that I think often gets missed. The relevant question is not "how likely is it that cryonics will work?" but "how likely is it that cryonics will both work and be needed?". A substantial amount of the probability that cryonics does something useful, I think, comes from scenarios where there's huge technological progress within the next century or thereabouts (because if it takes longer then there's much less chance that the cryonics companies are still around and haven't lost their patients in accidents, wars, etc.) -- but conditional on that it's quite likely that the huge technological progress actually happens fast enough that someone reasonably young (like Chris) ends up getting magical life extension without needing to die and be revived first.
So the window within which there's value in signing up for cryonics is where huge progress happens soon but not too soon. You're betting on an upper as well as a lower bound to the rate of progress.
There's a slightly subtle point in this area that I think often gets missed.
I have seen a number of people make (and withdraw) this point, but it doesn't make sense, since both the costs and benefits change (you stop buying life insurance when you no longer need it, so costs decline in the same ballpark as benefits).
Contrast with the following question:
"Why buy fire insurance for 2014, if in 2075 anti-fire technology will be so advanced that fire losses are negligible?"
You pay for fire insurance this year to guard against the chance of fire this year. If fire risk goes down, the price of fire insurance goes down too, and you can cancel your insurance at will.
Background:
On the most recent LessWrong readership survey, I assigned a probability of 0.30 on the cryonics question. I had previously been persuaded to sign up for cryonics by reading the sequences, but this thread and particularly this comment lowered my estimate of the chances of cryonics working considerably. Also relevant from the same thread was ciphergoth's comment:
Based on this, I think there's a substantial chance that there's information out there that would convince me that the folks who dismiss cryonics as pseudoscience are essentially correct, that the right answer to the survey question was epsilon. I've seen what seem like convincing objections to cryonics, and it seems possible that an expanded version of those arguments, with full references and replies to pro-cryonics arguments, would convince me. Or someone could just go to the trouble of showing that a large majority of cryobiologists really do think cryopreserved people are information-theoretically dead.
However, it's not clear to me how well worth my time it is to seek out such information. It seems coming up with decisive information would be hard, especially since e.g. ciphergoth has put a lot of energy into trying to figure out what the experts think about cryonics and come away without a clear answer. And part of the reason I signed up for cryonics in the first place is because it doesn't cost me much: the largest component is the life insurance for funding, only $50 / month.
So I've decided to put a bounty on being persuaded to cancel my cryonics subscription. If no one succeeds in convincing me, it costs me nothing, and if someone does succeed in convincing me the cost is less than the cost of being signed up for cryonics for a year. And yes, I'm aware that providing one-sided financial incentives like this requires me to take the fact that I've done this into account when evaluating anti-cryonics arguments, and apply extra scrutiny to them.
Note that there are several issues that ultimately go in to whether you should sign up for cryonics (the neuroscience / evaluation of current technology, estimate of the probability of a "good" future, various philosophical issues), I anticipate the greatest chance of being persuaded from scientific arguments. In particular, I find questions about personal identity and consciousness of uploads made from preserved brains confusing, but think there are very few people in the world, if any, who are likely to have much chance of getting me un-confused about those issues. The offer is blind to the exact nature of the arguments given, but I mostly foresee being persuaded by the neuroscience arguments.
And of course, I'm happy to listen to people tell me why the anti-cryonics arguments are wrong and I should stay signed up for cryonics. There's just no prize for doing so.