Google+ is giving users a pre-post option to disable comments or prevent content from being re-shared. Other additions so far this month include notifications in the browser bar and the release of public APIs for Plus search, comments, and +1s.
Locking Down Plus Posts
As announced by Ebby Amirebrahimi (a member of the Google+ sharing team), users now have the option to disable comments or lock a post prior to publishing that post. Locking a post prevents other users from re-sharing the content.
Previously, users could disable comments and lock sharing post-publication, making the process longer than necessary and leaving a window of vulnerability. Now users can access the "disable comments" and "lock this post" options directly from the sharing button (the same Google+ element where you select which circles you want to share with).
Along with the updated sharing comes a minor aesthetic update: Users can now see when they have new notifications via their browser bar. As noted by The Next Web, this may serve as an incentive for users to keep a tab tuned to Google+.
Search, Comments, and +1 APIs Released
Google released the first Plus API on September 15th, when they gave access to basic framework elements and public data. Then they released the API for Hangouts, the group video chat service, on September 20th. Now the APIs for Plus search, +1s, and comments are also available.
These additions will help third-party applications access key features of Google+, making those apps (as ReadWriteWeb puts it) "a little more interesting." The addition may also give Google's +1 additional presence and power.