As of today, when you hit the share icon on a Google+ post, you'll automatically be taken to a Google+ reshare of the post. Previously, users were given an option between Google+ and other social options. This was done in an effort to reduce the number of clicks it took you to reshare Google+ content on Google+. While there is no longer direct share capability to other social sites, copy/paste from the address bar in your browser still works just fine.
We hope this will make your experience here a little bit more seamless and thanks for the feedback that got us here!