Google announced that when a URL is too long, they might now replace the URL in the Google search results with a "site hierarchy display," or what appears to look more like a breadcrumb trail. Technically, Google analyzes a site's breadcrumb trail and shows this instead for a "small percentage of search results."
I personally cannot trigger it yet, but many are now seeing it. Here is one example:
Google actually has been testing this since August. We have reports of this at Search Engine Land, RedCardinal.ie and Rob Hammond.
Forum discussion at Cre8asite Forums and WebmasterWorld.