Google has announced a few new features for Google+, including a "volume control" that helps highlight posts from certain circles, a new notifications bar, and a new photo viewing experience.
The biggest update is the "volume control", which works in a similar way to Facebook's highlighted stories, but also allows you to fine-tune the controls. Each of your circles will get a control slider so you can tune the content in those circles to display more or less often in your feed. Sliding it all the way up will ensure you won't miss any updates posted by anyone in that circle.
The notification bar gets an update as well and now includes information about what is actually happening on your page instead of short and vague clues. If you're a Google+ Pages owner you can assign up to 50 administrators and get a better count of users engaged on your page. Finally, the photo display gets a complete overhaul and adds better comment clarity and a new tagging method. These updates will be rolling out to users over the course of the next few days.
Google+: A few big improvements before the New Year [The Official Google Blog]