the fact the "how" will depend on technology that hasn't been invented yet arouses a great deal of skepticism.
Why should it? There's plenty of indirect evidence that this is technology that will be invented eventually, if there's a future at all for it to be invented in. There are already three general research paths we know of that can lead to successful reanimation: nanotech, biotech, and uploading. All three of these, in all their various incarnations, would need to fizzle and uniformly continue to produce no results in this area, for hundreds of years before cryonics will have failed. In short, the predictions we're making pretty much have to somehow contradict the laws of physics. They don't have to simply be optimistic in order to fail to happen for hundreds, perhaps thousands of years of rich scientific progress -- they have to be totally bonkers.
So we should just assume that any future technology we would like to imagine is assured of happening, given enough time?
If that is the case then I don't need to waste my time with cryonics because I am assured I will be resurrected in a Tipler Omega Point.
Luke Parrish points me to what is clearly by far the most serious critique of cryonics ever written: a 57-page treatment by Evelina Martinenaite and Juliette Tavenier, presented as a 3rd semester project at Roskilde University in Denmark supervised by Ole Andersen.
Full paper