I speak regularly on social media. Admittedly I rarely mention Google+. Inevitably someone will ask about the social media outlet. I frankly pass off Google+. Mainly because most attendees are trying to grasp Facebook and hashtags.
Now there is a solid report on the future of Google+ and research behind the article: The Future of Google+, What New Research Reveals
Read it and make up your own mind.
By the way, I would welcome the opportunity to talk about my speaking on social media and/or email marketing. Feel free to call or email me.