No, Google didn't launch their long rumored social network/app (Google Me) but they did enhance their search engine to include social results. So now when you search you'll start seeing results influenced by the posts/shares of people in your social circle (of course only when you are logged in to gmail or iGoogle).
Basically Google is enhancing their search algorithm to include relationships as a signal of relevance to you the searcher. For example, when I do a search on "Google social search" Google now shows me some results that have been created and/or shared by friends in my gmail contacts or people I follow on Twitter. As you can see in this screen grab, Google is displaying a story shared by Paul who works with me at ReachLocal and another that has been tweeted by our official twitter account that I follow.
Are these search results more relevant to me than others that Google could have displayed? Probably so but then again I don't know what the other results would have been...maybe a great article by Wired or another publication I read but am not connected to socially. The other potential problem I foresee is that I follow a lot of people on Twitter whom I don't really know well and certainly don't want them impacting my search results. So far I don't see a way to set filters so it looks like an all or nothing proposition. I'll keep trying it for a while but the jury is out.
If you want to learn how to enable this for your Google searches watch their short video below and read the official blog post.