About two weeks ago, Google News began testing Twitter integration. Google News and Google Search, now seems to be testing "shared by" links, along with "recent update" links.
Malcolm Coles posted screen captures of the new Google News experiments.
The image below are freshly searched and caputred -- and it shows a "shared by" followed by a number. Clicking on the "shared by" link takes you to a link command in Google's real time search index.
Note; These features don't need to be logged into Google account, nor did it need to be integrate Google News with Twitter.
And, the picture below shows "recent updates" links: