Well, more information has become available via SEObytheSea.
“A method includes generating search results in response to a user query, where at least one of the search results includes a group of links. The group of links may represent links to web pages within a same web site and may be identified based on at least one factor associated with the links. The method may also include providing the search results to the user.”
My analysis of the process and the need come down to:
1. This could be a response to gather data about what the users intent is when providing a specific query based upon users activity.
2. This could be a way to more effectively use the real estate on the results page because subsequent pages, even though indented, take more space than do the new sitelinks.
Response to the first question from Bill:
“For people using a query in an informational manner, these results provide a sort of a preview. One of the criteria in the quality scores mentioned in the patent application is that a page may be something where people can make a purchase, So, there’s a shortcut to one of the most popular product/sales pages for people performing transactional queries.”
The second hypothesis is still purely suspect, however, it is well known that Google’s intent is to provide users with what they are looking for, and this makes the second hypothesis to make common sense.