Not much. It appears that links are still good, whether they are one-way or reciprocal. Relevance matters. The links should originate on high-quality websites.
Google is confused about page rank and trust ranking. They will figure it out later. In the meantime, do not freak if your page rank tanks.
Google Algorithm Update Analysis-read complete article
From the article:
In short, I would expect that with an update late this week or over the weekend we're going to see a shift back to last week's results (or something very close to it) after which they'll work on the issues they've experienced and launch a new (hopefully improved) algorithm shift the following weekend. And so, if you've enjoyed a sudden jump from page 6 to top 3, don't pop the cork on the champaign too quickly and if you've noticed some drops, don't panic. More adjustments to this algorithm are necessary and, if you've used solid SEO practices and been consistent and varied in your link building tactics – keep at it and your rankings will return.