Just joined Google plus circles, this is Google's big push to compete with Facebook in the social search arena after having dumped their agreement with twitter. It will be significant if it ever gets traction because google plus data is public and searchable unlike facebook's data right now,
Bay Area Inbound Marketing Blog
Inbound links are quickly becoming a broken metric. At the same time, social media is quickly escalating as a ranking factor for search engines. While inbound links still matter and are a decent factor for judging the authority of a website or page, social media provides search engines with key data points that they have long been lacking.