Chatter: Encryption for Chatter, Pinned Posts, Top Groups, and Trailhead Theme

Encryption for Chatter is generally available and includes more fields. Pin a post to the top of a group or topics feed (beta), and discover which groups have the most activity. Groups and user profiles get a new Trailhead look.
Available in: Group, Professional, Enterprise, Performance, Unlimited, Contact Manager, and Developer Editions