Google+ pages today gets an additional role called Communication Manager besides the Owner and Manager roles.
More details about the announcement (according to John Kilcline of Google)
Many brands and businesses have employees who focus on audience engagement — from posting content, to answering questions, to just keeping things fun. Such people are critical for connecting with followers, but they don’t need full access to a page’s online presence. Only the communication parts. That’s why we’re rolling out a new role (http://goo.gl/j2vhfg) for Google+ pages — the Communication Manager — that reflects this responsibility.
Communication Managers can post and reply to followers, as well as use features like Communities and Events. But they can’t edit the Google+ page, its managers, or any connected YouTube channels (http://goo.gl/vnCbJA). This way they can focus on outreach, and page owners can limit access to key administrative functions.
More information about the new role is available here: http://goo.gl/j2vhfg. To start assigning roles, simply visit the “Managers” tab of your Google+ Dashboard: plus.google.com/dashboard.