To celebrate Windows 10's one billion active users, Microsoft's Panos Panay posted on Intragram a video showing the development of Windows, along with Windows 10. The video reveals some characteristics which are to appear on Insiders the next period.
To be more specific, the video reveals a new Start Menu that looks like it will finally come to Windows 10. The new Start menu shows colorless boxes to pin applications without the color you selected. Live Tiles still exist.
The video also introduces a brand new File Explorer. It's actually the same modern UWP app that comes with Windows 10, but now it looks like it's improved a lot. Microsoft gives priority in its development, as it will be used by default in the upcoming Windows 10.
Finally, in the following video you will also see a new context menu. It looks very nice with the Windows 10 light theme and it seems to include a new 'Back' entry.
Last but not least in the Microsoft video is the calendar application UI:
Watch the video at Instagram.