In Google's search results, they've always included the URL to the link associated with a given result. The URL is set in green text at the bottom of the result. Now, they're replacing some of those URLs with site hierarchies.
Let's say you're searching for cat toys. Previously you may have seen:
http://ping.fm/xFOFi
Now you may see:
Domain.com > Example > Cat Toys
Here's an example as seen at the Official Google Blog:
The root domain will always show. If the site's hierarchy is deep, you may see an elipses to represent skipped categories:
Domain.com > .....>Example > Cat Toys
As with all major changes at Google, this is a rolling update. So if you don't see it, sit tight. It's rolling out globally over the next few days.
