People choose from among many options for their bodies after death. Some choose to be buried, some choose cremation. Some choose to donate their bodies to science. That last is precisely what happens with cryonics: in addition to helping to answer the obvious question of will future revival from cold storage be possible,
This claim is factually false. Cyronics organizations don't use their customers' bodies for research, and in general they don't do much research of any kind.
many developments in cryonics help modern medicine with the development of better preservation for organ transplantation and blood volume expanders.
As far as I know, in over 50 years of existence, cryonics didn't develop or improve any technique for medicine to use.
EDIT:
Luke Parrish mentioned one in the comments below.
This claim is factually false. Cyronics organizations don't use their customers' bodies for research, and in general they don't do much research of any kind.
You have clearly never read the Alcor case reports. Whether you view them with horror-at-the-ineptitude, or awe-at-the-learning-process, they're clearly having all sorts of fun experimenting with the bodies.
Of course, whether this is useful research is up to you to decide, but it's clear that the "preservation" side is still rather experimental. They do at least document all of it, too.
Aaron Winborn writes:
Blog post: http://aaronwinborn.com/blogs/aaron/open-source-software-developer-terminal-illness-hopes-opt-out-death
Hacker news discussion: http://news.ycombinator.com/item?id=5211602