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:
You do not need to rot13 anything about HP:MoR or the original Harry Potter series unless you are posting insider information from Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).
If there is evidence for X in MOR and/or canon then it's fine to post about X without rot13, even if you also have heard privately from Eliezer that X is true. But you should not post that "Eliezer said X is true" unless you use rot13.
This would make Draco's statement that muggles don't have souls accurate. Combined with McGonagall's statement that AK strikes directly at the soul, it would seem to imply that (1) AK should have no effect on muggles, and (2) AK should be nonlethal, only rendering the wizard nonmagical.
Canonically, AK causes destructive side effects (inanimate objects' blowing up when hit, etc). It could be that it strikes at the soul, severing a Wizard from their magical power, and additionally causes a blast that would kill an ordinary Muggle (but not a Wizard that remained a Wizard). So it kills Wizards by a two-step process, and Muggles by one. However, modern Muggle technology might be able to defend against it, unbeknownst to the Wizards.
I think that this makes AK a little more complicated than it should be. But the canonical AK (and especially the AK as seen in the movies) already is more complicated than it should be.