netmeg - 2:45 pm on Aug 1, 2012 (gmt 0)
One of my newer sites is now showing up in the knowledge graph spot for its top keyword (which also recently gained sitelinks) It's not a big brand, but I'm trying to make it into an authority site. All I did was add a post to a long dormant Google+ page. Interestingly it did NOT work for any of my other sites, even the ones that are more authoritative and have been around longer, and that also have Google+ posts.
I dunno if I stumbled on a bug or the beginnings of a wider rollout.