The short answer? Not very much — if anything — especially given the landscape of current, more social internet traffic. For the uninitiated, “nofollow” is an SEO-er’s worst nightmare. Internet links of type “nofollow” don’t get weighted by search engines as credible content. Therefore, search engines are less likely to increase your search engine result page ranking. But the link still exists on a page to send humans along their way (what really counts), and gone are the days of link juice via the mighty Wikipedia with some speculating Digg and others will soon follow.
If you run a link farm or use black-hat SEO techniques, you’re job just got a bit harder and will continue to do so. On the other hand, if you understand traffic-driving content, solid copywriting, and content optimization for humans, you and your site will do just fine. As search listings get more bloated, people want to be referred by trusted individuals or a consensus group, not some outdated search algorithm. Hence, the “nofollow” link is a good thing to counter spam while humans still get directed to the best content. Remember: search engines follow where humans go, not the other way around. Optimize your content and you’ll do just fine. Need another buzz word? Call it SEO 2.0. Okay don’t. Just call it smart content.