EDIT: New discussion thread here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With two chapters recently the previous thread has very quickly reached 500 comments. The latest chapter as of 17th March 2012 is Ch. 79.
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. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
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, ten.
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Eliezer Yudkowsky which is not supposed to be publicly available (which includes public statements by Eliezer that have been retracted).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.
Dumbledore has no difficulty with action when needed(TSPE, most notably), but he's been burned too many times by the cost of his efforts to be eager about it. He'd much prefer to stop the war by passive deeds(sequestering Harry, poisoning Voldemort's father's grave, etc.), and not risk the bloodshed that open war would cause, or even the loss of political capital caused by a showdown with Lucius Malfoy. There's bound to be a big difference between an 11 year old sci-fi fan and a hundredish year old veteran when it comes to eagerness to do harm, and frankly I think that Dumbledore's caution is at least as justified as Harry's sneakiness when it comes to planning a war. After all, Harry's never seen one of his incredibly clever plots fail, and he's eleven, so he is naturally going to be far too eager. Inaction isn't always wrong.