Yes definately, anything google related will get priority in the SERPs. google fox news, its google profile ranks above wiki, twitter and facebook even though these are more established.
Yeh I've been seeing a lot of this recently, but tbh I like it, Google are most of our sources for traffic, so why complain? Use it to your advantage!
It is really going to Boost the SEO as well as Traffic of websites. It is better to gain as much +1's and Circles as you can. They are very effective now.
Google+ is Google property so thats mean it will be also nice and very advantage for advertising our business in Google+