UPDATE: Some of my better-read compatriots have pointed me towards Greg Sterling’s article from April about how Google is using the layout below to appease anti-competition complaints in Europe. So take my theories below as pure entertainment, as it should be.
I can’t find another example of this, or a full SERP screenshot, but I think there is one of two things going on here: 1) Google is doing this to address anti-competition complaints in Europe and/or – ACTUALLY THAT’S PRETTY MUCH WHAT IT IS – THE REST OF THIS IS JUST FOR FUN: 2) this kind of layout could be suggestive of Google’s desire to deemphasize local directories in the SERPs while still providing access to those users who want them. This is pure speculation, but over the past year, I have noticed that more and more truly local sites are showing up in the organic results for local queries.
This may be symptomatic of Google wanting to favor these sites over the national directories like Yelp and Yell, or it may simply be the fact that more local businesses are doing SEO. I have always felt that a well-SEO’d local business site should always be able to outrank most directories for any query in the non-local section of the SERP.
Perhaps this is Google signaling that your local directory better not be a generic set of business listings which adds little value to the SERP. If this, or some version like this, becomes the default SERP display, the implication is that you better have a brand that is going to make people click (and your brand name better be pretty short).
Some further reading on the matter: