An old feature from Google Plus is the ability to disable commenting and lock down a post after it’s published, allowing you to keep your friends from sharing the post to others, or to prevent comments on a post.
Starting today, it’s now possible to adjust those settings before the post is posted, allowing you to fine tune the posts. You can choose to change those preferences in the new drop box next to the share bar. Check out this video to see how:
In other news, the Google Plus API is now enhanced to allow developers to access Google+ search, and to retrieve comments, shares and +1s of a specific post. However, the access is still read-only, and apps cannot write new comments, for example. [Source]