The SEO trends that I have been able to discern come from the newsletter. They are based on the piece from the Librarians' Internet Index head. In her article, the LII's director mentions how her staff make judgements for the LII about what sites are authoritative and trustworthy. They are guided by 5 points. "We rely primarily on what we call the 'big five show-stoppers': availability, credibility, authorship, external links and legality."
From here on in, I'm going to quote and explain what Schneider has written about each of the 5 elements. More interestingly, I will then comment on how I think SEOs should adapt, given the developments Google will naturally make in their algorithms from the LII's insight. Of course, developing your SEO strategy means you believe the premises of my argument, namely, that Google is working with librarians to improve its own searching. If you don't think I've proven that point sufficiently though, then by all means, stop reading right now.
1) Availability – "Is the site up and running? Is the information freely available?"
Schneider is referring to the level of accessibility of the information on a site. Considering that spammy sites often try to make a buck by offering access to their content for a "subscription fee" that "automatically renews" the charge on your credit card if you don't cancel, this is a policy partly aimed at fighting spammy sites. It takes a characteristic of theirs and uses it to block them.
The catch is that some sites with limited access to content that aren't spammy might get hurt if this becomes too black and white in Google's algorithms. The LII's director herself recognizes that not all sites with limited content are spam: "Of course, this isn't a hard-and-fast rule. We don't reject a site just because it has some information behind a wall." I trust Google's engineers will be able to figure out the programming.
I just want to digress for a moment here. As is common knowledge, the Internet's oldest industry - the porn industry - commonly offers content for sale. So in the LII's opposition to content-for-sale websites, I see a bit of a Victorian undercurrent, an undercurrent that disdains pornography and treats it accordingly. While I'm not taking a position on pornography, I think it's a caveat worth noting that part of this policy may be motivated by non-objective factors.
That's just my interpretation of things, though; Schneider writes that "we [the LII] pass along only freely available sites because our working assumption is that when you're hunting for information, either for yourself or for a library patron, free access is good." Incidentally, Schneider's comment is further evidence of the quid pro quo I mentioned above, in that a librarian is endorsing Google's mission statement. Recall that Google's mission is to make the world's information freely available.