A few minutes ago I searched for a product on google.com, and right below the display URL and Google checkout icon of one of the advertisers was a plus box with the label "Products from this Advertiser". Expanding the plus box showed 3 products, descriptions, and links to the merchant's site.
I saw this only in the Ad Preview Tool, and I couldn't get it back after I cleared my cookies. I'm assuming it's a new feature that they're testing.
Has anyone seen more details about it?