We've offered a "Similar" feature on results for a while now as a way to discover new, useful sites, but it hasn't been too visible. Since we've been continuously improving this feature and we think it's really useful, we're now going to start showing these alternative sites more prominently. Starting this week, for queries where similar sites are likely to be helpful, we’ll display a list of "Pages similar" at the bottom of the results page.
I have been noticing the gradual improvement of "Similar" results, especially over the past year. It will be nice to see them getting more play - could mean a bit more traffic from organic search, and the kind that would be new to a site, too.