Google Changing URL Structure
Well-structured URLs offer users a quick hint about the page topic and how the page fits within the website. To help mobile searchers understand your website better when its shown in the mobile search results, today Google is updating the algorithms that display URLs in the search results to better reflect the names of websites. Now Google will be using the real-world name of the site instead of the domain name, and the URL structure of the sites in a breadcrumbs-like format.
See the full article in the Google Webmaster Post