It's totally unscientific! It's pure pseudo-science.
> If you accept the physicalist tenet that the brain is a machine
...okay...
> that the mind is the result of information processing, that there is no unmaterial "ghost" an so on then trying to preserve the "state variables" of that meat computer with vitrification is perfectly reasonable, specially compared with the only current alternative, total annihilation.
Well, no. We don't know what the mind is, nor how it works. We've only recently discovered that your unconscious self does stuff before your conscious self decides to do it. (http://exploringthemind.com/the-mind/brain-scans-can-reveal-...) {With interesting video clip}.
Freezing your brain is as scientific as stitching corpse-body-parts together to create a living human.