The newest Office 365 Roadmap has some interesting features planned for Outlook.
March 18 2016
The one I'm looking forward to the most has to be a Focused Inbox, like the one in Outlook for iOS and Android. While I'm mostly happy with Clutter's ability to clean up my Inbox by moving less important email to a new folder, it's really only useful in Outlook. When I read mail on my devices I don't have a unified experience, like I do with the Focused Inbox. Checking the Clutter folders for each account takes time. Look for this in Outlook on Windows, Mac, and in Outlook on the web. How soon? Who knows... it's still in development. Does this mean the hated Clutter folder is going away? Time will tell, but I believe so, since it's redundant to have both a Focused Inbox and a Clutter folder.
The Archive button that surfaced in recent Outlook 2016 builds will be added to Outlook for Mac, matching the capability in Outlook on the web and Outlook on devices. Archive moves the selected message to the designated Archive folder and works with Exchange, Outlook.com, Gmail, and other IMAP providers.
Better integration between OneDrive for Business and Outlook is coming to Outlook for devices and Outlook on the desktop, matching the capability found in Outlook on the web. Outlook 2016 users will be able to automatically upload attachments to OneDrive or OneDrive for Business to share as a cloud attachment. Outlook for iOS & Android will be able to view, send files from and save attachments to OneDrive for Business.
While we don't have an exact date for any of these features, they are currently being developed.