Support for Apple iCloud calendar
It's extremely important to sync Calendar App with Outlook calendar to let me use Outlook for Mac instead of Mail App.
Chris Nelson commented
I want to use Outlook (and Office) on my Mac but for the time being, the only way I can integrate my work (exchange) and my family (iCloud) calendars is to use the default Mac program, Calendar. It hurts the value proposition of Office for it to not work as well as the programs that come already bundled with my computer.