When we look at policy for Google+, the same considerations as we've been discussing are important.
Point-of-Contact: Your company should determine one person or a team internally that can handle all of Google+ interaction.
Content: Your company should determine a policy stating which employees post on behalf of the company, so there is no confusion about who can represent the company's interests. This should also include a policy on whether or not employees are allowed to respond to posts through their personal profiles.
Comment Response: Your company should create a protocol on who responds to comments and on how negative responses are handled.
Be sure to remind employees to be careful when posting. Since Google+ has so many different sharing options, it's possible to share something with the wrong circle. A Google employee actually made this mistake shortly after the platform came out in October 2011 by posting a rant complaining about the Google+ platform.