Google has just replaced the Google Webmaster Guidelines document, known as the holy-grail of SEO guidelines for most in our community. It seems a lot of the content has been revised and updated, which may be part of the new webmaster home from Google.
It is hard to summarize all the changes, but the most visible one is that it is no longer just a single long page, it is now broken into expandable content blocks (which Google doesn't recommend). It is broken into:
(A) General Guidelines with indexing, content and usability. (B) Quality Guidelines with basics and specifics.
Google has only updated the content in the "general guidelines" section. The "quality guidelines" section seems untouched. There is nothing glaring in the new general guidelines outside of adding a lot more content, reorganizing a bunch of those guidelines and rewording some of them.
Here is a picture from the other day, you can click to expand all of them:
Here are pictures of the new one both expanded and collapsed:
I have yet to read through each very closely to compare what was pulled out and what was added, I hope to do that a bit later.
Forum discussion at Google+.
Update: We now have published a detailed overview of what has changed with the guidelines.
