In a sense, Office 2016 is an incremental update that allows it to catch up to Google Drive and Docs as a whole.
Real-time co-authoring is now a feature, Cortana integration debuts for assistance, better search has been engineered, better cross-platform compatibility, chat with built-in Bing searches, and finally, business integration to the point where DLP (Data Loss Prevention) is built-in and Multifactor Authentication makes it easier to operate on the software suite if away from the corporate network.
As for design, the interface remains mostly unchanged, but updated of course, to fall in similar aesthetic quality with the new Windows 10.
Office 2016 is now available for Office 365 subscribers or as a one-time purchase on Mac — pick your poison, essentially.
Via: Office Blog