Part of the recent Google Update that was really not a full update, by any standards, was that the Google Related command has been updated. Back in mid-July we reported that Related Search Command Changes at Google.com and it looks like more changes have occurred to it.
The related command is when you type related:www.domain.com into Google or click on the "Similar pages" link in the search results.
How do you test the new results? Use the IP 18.104.22.168 and give it a shot. They seem much more on topic then they are now at Google.com. There is currently a nice result set for related:www.seroundtable.com.
Forum discussion WebmasterWorld.