Google won two patents a few days ago.
The first one is called "Document retrieval system with access control" and the second one "method for searching and recommending objects from a categorically organized information repository".
Behind the lingo is the fact that Google is gradually shifting pieces around pieces of a gigantic puzzle. The first patent, for example, talks about "electronic document retrieval and in particular to access control for documents available on storage devices located remotely from each other".
Unlike what the post actually says, it is not about reverts or rolling back. It is about access to information based on an ID. It might even be the key to solve the headache that Google has with the US government right now regarding privacy issues. Look at the bottom of the page (http://tinyurl.com/ql3b5) here. Very intriguing and exciting; especially the reference to the FBI.
The second patent's document is much longer but treats an altogether different field. From the abstract, it seems that Google is going to use it Google toolbar as a way to counteract the growing influence of Delicio.us and Technorati, when it comes to tagging; The terms "content pointer" and "distributed program" point in that direction.