I would agree with Mike.
Search Engine Land and Moz are looking at it from an outside view and crunch a ton of numbers to figure out what sways SEO. Matt Cutts wants to get rid of spammers, if he clearly comes out and states it does make a difference and effects your ranking. I can see a ton of spammers flooding a Google+, which would be great for the company from a birds eye view.
I wouldn't be overly concerned about the specifics in SEO ranking. Focus more on developing a great website with Google Webmaster guidelines in mind (clean code is super important!), make sure your website looks great to consumers (lowers bounce rate and increases brand awareness) and have your website load within 2 seconds. Don't forget to add great and valuable content to your site. It will naturally start to get ranked (reach out to journalists to get mentions + link backs!).