The field of Search Engine Optimization may someday encompass countermeasures to prevent search engines from scraping too effectively. It's likely to continue to be an arms race as the search engines become better and the web masters adapt, but that adaptation may someday be geared at hindering, not helping, the search engine to increase non-robot traffic to the site.
I believe that Google Search frowns upon this practice. Though, one can argue that there are different shades of gray, especially when supporting different display types and sizes, or when presenting different pages depending on the referrer.
They are kind of an interesting solution, but it seems like it might be better suited to only showing up when you click on "more from this domain" (but at that point the whole results page is for that domain, so it could probably be organized differently).
