Nothing about the process of sleep requires that it be permanent, so sleep does not have the inherent property of permanence.
What makes it inherently permanent? The only difference between sleep, cryostasis, and being shot in the head is how likely you are to be revived. It's never certain, and it's never impossible. Death is permanent by definition, but that just means we're never quite certain anybody is dead.
Also, if intelligence "stops" and "starts" from the same physical generator, i.e. the brain, (which isn't what happens with sleep) then it is the same one.
Pretty much everyone's brain is made of the same quarks and leptons, so the same physical generator doesn't exactly narrow it down any. I would explain what I mean by that, but the link you have already does it.
Yes, it does. The link says, actually:
You will even be able to see, I hope, that if your brain were non-destructively frozen (e.g. by vitrification in liquid nitrogen); and a computer model of the synapses, neural states, and other brain behaviors were constructed a hundred years later; then it would preserve exactly everything about you that was preserved by going to sleep one night and waking up the next morning.
The physical generator includes the configuration of those quarks and leptons, which is what gives rise to the specific intelligence.
Update: Discussion has moved on to a new thread.
The load more comments links are getting annoying (at least if you're not logged in), so it's time for a new Harry Potter and the Methods of Rationality discussion thread. We're also approaching the traditional 500-comment mark, but I think that hidden comments provide more appropriate joints to carve these threads at. So as of chapter 67, this is the place to share your thoughts about Eliezer Yudkowsky's Harry Potter fanfic.
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six. The fanfiction.net author page is the central author-controlled HPMOR clearinghouse with links to the RSS feed, pdf version, TV Tropes pages, fan art, and more, and AdeleneDawner has kept an archive of Author's Notes.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: