Office 2016 is still in preview form ahead of final release sometime this year. Microsoft also confirmed that real-time co-authoring is coming to Word 2016 desktop in a future release.
Outlook is also getting a big update; attachments will automatically upload to the cloud instead of being attached to the email directly so that you can send larger files much more easily.
You can try the latest Office 2016 preview here ahead of its release.
➤ Modern productivity–Office news at Ignite [Office blog]