Almost all science-fiction writers have opted not to make personal arrangements for cryonics.
This suggests to me that a generally open mind toward the future may be necessary but not sufficient. A certain personality type may be necessary too. I can't define it, but I do notice a difference between most of my friends in the science-fiction community, and people in cryonics.
Joe Haldeman and Frederik Pohl apparently made up their minds longer ago that they prefer to die permanently. I have had serious and lengthy discussions with both of them on the topic. There are ironies in both cases. Haldeman was indirectly responsible for me learning about Alcor, after he made an impromptu visit to Alcor during an academic conference in Riverside. Pohl of course wrote a whole novel using cryonics as a concept, and he helped Robert Ettinger to find a publisher for The Prospect of Immortality. (Prior to that, as I understand it, Ettinger had circulated only a small privately published edition.) Without Pohl, cryonics might have been delayed and might have been promoted by someone else in a very different way.
I went through all the usual arguments in favor of cryonics with both of these writers. Fred Pohl conceded each point logically, but at the end of the conversation he said something like, "I don't know why, but for some reason I just don't like the idea." Joe Haldeman had some really creative objections, one of which being that revival might cause extreme pain, and having been wounded in Vietnam, he knew a lot about pain. I suggested to him that if revival was going to happen at all, it would occur long after medicine acquired the capability to achieve good pain management. He had to agree that this made sense, but then backtracked to the issue of money. And so it went on. I think really he felt the same way as Pohl: For some reason he just didn't like the idea.
I disagree with Rudi Hoffman's post on CryoNet blaming cryonics advocates for failing to sell their wares effectively. I do not believe that anyone can, will, or could have sold cryonics to Clarke, Heinlein, Asimov, Pohl, Haldeman, or most other science-fiction writers.