Google has completely rewritten the resource their team of quality raters use to rate websites for Google. While the document is supposed to be a secret, it's already been leaked onto the Internet. Some highlights:
More emphasis on a website's “expertise, authoritativeness and trustworthiness.” Lack of any one of these 3 components can give the page a low quality rating.
Many ads on a page equal low quality. If there's nothing but ads above the fold, or the content is broken up by ads, or if there is an overabundance of ads anywhere on the site, it can mean a low ranking.
Pop up ads are bad as well. No word on whether or not this includes an incentive to join your list.
Deceptive ad placement such as tricking a reader into clicking an ad when they think they're clicking an article is a major no-no.
Quality supplementary content is important. For example, links to relevant posts, and relevant additional resources are a major plus.
Site reputation is more important than ever to Google. And Google is placing a greater emphasis on the presence of “About us” and “Contact info” pages.
What you need to know: Activity of the raters is used by engineers of the algorithm to make changes to the algorithm.
Here's Search Engine Watch's take on the changes, along with a video from Matt Cutts explaining how Google uses human raters in web search.
Social tagging: Google > rank > rating
