(The HPMOR discussion thread after this one is here.)
The previous thread is over the 500-comment threshold, so let's start a new Harry Potter and the Methods of Rationality discussion thread. This is the place to discuss Eliezer Yudkowsky's Harry Potter fanfic and anything related to it. The latest chapter as of 09/09/2011 is Ch. 77.
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, seven, eight. The fanfiction.net author page is the central location for information about updates and links to HPMOR-related goodies, 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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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.
I'm one of the people who was confused by the Merlin thing and said as such in my review that I wasn't sure if it was lying or not. In that version, the Obliviation was a lot less obvious. My initial reading was that the entity in question was trying to appear (probably untruthfully) to have been testing Hermione previously and was now ready to reveal itself in its true, nice form. It even occurred to me that it might even have been its actual form with it finally happy that it could appear as a nice being rather than as some terrible mystery. I was in particular thinking of the part in the Chronicles of Prydain where the companions are shocked to find out that the nasty looking hags true form might actually be beautiful young women. In that text they call it out explicitly.
Still, the switch to the repeated ... made it really clear what was going on in a really blunt, squicktastic fashion. I have to agree with pedanterrific that you may want to be careful not to play to the lowest common denominator of ff.