7. Added App Resizing Features
With Windows 8, Microsoft introduced the ability to put two apps side by side. With Windows 8.1, you can adjust the size of those apps more precisely. Instead of a smaller app on the side of a larger app, you can split the apps evenly on the screen or resize them to your liking.
8. More Keyboard and Mouse Support
Microsoft is also emphasizing that it has made it easier to use Windows without a touchscreen. When you hover your mouse in the corners you can customize it so it takes you back to the all apps page or go back to a previous app. There has also been improved multimonitor support so you can display multiple apps on all monitors or use the desktop side-by-side with other apps.
Windows 8.1 will be out later this year, but will be available for developers and early adopters to try out today.