There are conflcting reports about the current state of Google Plus.
A Techcrunch article, Raise your Hand if your still using Google+, seems to indicate the the fad is dying off and no one is really using it any longer. Hitwise is also reporting the dwindling numbers.
Contrary to that, Mashable seems to think they still have hope with the launch of the new Google+ API.
I know my activity on G+ has SIGNIFICANTLY gone down. Time will tell, but the bottom line is G+ is going to have to significantly step it up to win back that market share.