If you mean this sort of thing http://www.kurzweilai.net/slate-this-is-your-brain-on-neural-implants, then he is barely arguing the point at all...this is miles below philosophy-grade thinking..he doesn't even set out a theory of selfhood, just appeals to intuitions. Absent Qualia is much better, although still not anything that should be called a proof.
I got started by Sharvy, It aint the meat its the motion, but my understanding was Kurzweil had something similar first. Maybe not. Just trying to give the devil his due.
I found this article on the Brain Preservation Foundation's blog that covers a lot of common theories of consciousness and shows how they kinna miss the point when it comes to determining if certain folks should or should not upload our brains if given the opportunity.
http://www.brainpreservation.org/not-all-theories-of-consciousness-are-created-equal-a-reply-to-robert-lawrence-kuhns-recent-article-in-skeptic-magazine/