And what about Snap, the nifty little feature that fills half of a Windows 8 screen? That's been improved as well. Every app in Windows 10 can be dynamically resized in a window, although it remains to be see how well this works in practice.
In Windows 8, apps can be snapped by clicking the Windows key and the left or right arrow, snapping them to the left or right of the screen. That fills half the screen. With Windows 10, up to four apps can be snapped per screen, maximizing your productivity.
What's neat, though, is that once you snap an app, Windows 10 suggests another, similar app that you might want to snap next to it, from a small collection of windows. The feature is intended to save you the hassle of hunting about through menus to actually construct a virtual desktop. Time will tell whether these suggestions will prove useful, but it's a good start.
You can see, however, that a number of different features – Snap Assist, windowed apps, virtual desktops – all flow somewhat organically into one another. I'm honestly interested to see what difference they make in my own daily workflow.