Managing contacts and emails is inherently social, so it isn't much of a surprise that some level of integration is being added between them. Why should you need to maintain two lists and categorizations of contacts, one for email and one for your social network? Well, for one, you probably don’t everyone in your contacts list, or even those you regularly communicate with in your social network — that much Google has learned from the Buzz launch fiasco — but you might still want your contact automatically updated as people update their own data. This is pretty much what the new Google integration offers.
In addition, Google Contacts now also uses your circle information to organize your contacts. This doesn't remove your existing contact groups, but overlays another management tool over the existing one. So now it is possible to view contacts within a circle.
As for GMail, Google circles are there as well. In addition to your labels for filtering email, GMail now offers Circles as a filtering option. Emails can be filtered based on which circles the participants in it belong to. Also, circles show up similar to labels in your conversation list. GMail now also allows you to add someone to your circles right from the contact widget on the right of the interface.
Another interesting feature added to Google is the ability to share photo attachments. Now if you get an image attached to an email, you can straight away click on the share button to share it on Google , rather than download it, and then reupload it to Google to share.
These changes aren't just integrating Google into other Google products, but also integrating users of other Google products into Google . With the massive audience that Google already commands this could have interesting consequences for their social network.
If this trend is to continue it would make sense to also integrate Google circles into Google Docs, making it possible to share documents in certain circles — Google added support for sharing documents with Google Groups long ago.
How far will this Google integration go? Right now it seems Google is only getting started.