Googleguy says there are tons of ways to optimize your site that search engines appreciate because it makes a site easier to crawl and index
Googleguy says to him, whitehats stay one side of their quality guidelines and blackhats are on the other side.
They do appreciate work that makes the site easier to crawl and index.
That thread has a lot of info on the current update... oddly named "florida".
Another good comment:
Googleguy says he's happy for anyone to define spam however they want, or even to say that it doesn't exist. He thinks Google has some pretty clear examples of spam in their quality guidelines, and people should still be aware of the quality guidelines.