(The HPMOR discussion thread after this one is here.)
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. There haven't been any chapters recently, but it looks like there are a bunch in the pipeline and the old thread is nearing 700 comments. The latest chapter as of 7th March 2012 is Ch. 77.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author's Notes.
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, nine.
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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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.
The first thing I noticed is that the list contains the Santa Claus messages and H&C appearances (14, 21, 35, 63, 77). Presumably all chapters that contain strong and deliberate hints at H&C's identity are on the list. I notice that neither the chapter where Remus talks about Sirius and Peter, nor the chapter where a prisoner is mumbling "I'm not serious [Sirius]" are on the list, so H&C is unlikely to be Sirius. On the other hand 65 which has Quirrel explain that the port key Santa Claus sent had a misleading description attached is not on the list either, so that may not be definite.
In 14 - Harry's Invisibility Cloak is not given by Santa Claus - the letter is unsigned unlike future letters - and is almost surely given by Dumbledore himself. Perhaps this is a hint toward the use of a time-turner? (Does Hermione know about Harry's time-turner yet? )
63 is on the list - where Harry actually receives the gift from Claus.
Also, 43-47 has Harry going deep into his dark side, that's probably more the clue than killing of the dementor.
OT - Whoa! I didn't realize that http://hpmor.com/chapter/58 had someone saying "I'm not serious" - awesome!