Earlier quoted context omitted.
He went in for cancer treatment, so he clearly wanted to avoid death, which is what the essay is about.
Christopher is largely dismissive of the life-extension techniques that transhumanists espouse, such as cryogenic preservation: http://www.vanityfair.com/culture/features/2010/11/hitchens-...
Firstly, Christopher is not dismissive of life-extension techniques that transhumanists espouse. If he could live longer right now due to a technique formerly classified a "espoused by transhumanists," he would choose to, as is evinced all over that essay. Rather, he is largely dismissive of life-extension techniques that don't work. The transhumanism part has nothing to do with it.
In that essay, cryonics is lumped in with the paragraph that discusses bad advice. So we can agree that Christopher considers cryonics as bad science, the same way he considers eating the granulated essence of the peach pit to prevent overwhelming growth of a malignant neoplasm bad science.
On the other hand, the rest of the essay discusses good science, that is, science which has been proven to work. He discusses its "near-miraculous" quality.
Perfusion of chemicals to preserve and prepare brain tissue is already textbook science, just not applied to whole brains. The case of Clive Wearing is one piece of an assortment of evidence that consciousness is a clever illusion (the philosopher of consciousness, Daniel Dennett, can say a lot here). Ultimately, cryonics is science that (by definition) has not been proved to work, but nonetheless serious science. Please don't deny that. Harvard neuroscientist Kenneth Hayworth explains this much better than I could, so I leave the floor to him:
http://brainpreservation.org/documents/killed_by_bad_philoso...
This issue is much too important to worry about what's distasteful.