This is a huge change for us iPad users. With it, Apple makes better use of the iPads larger size.
Multitasking is improved in many ways. You can have two documents from the same app side by side. In the slide-over view, you can swipe between apps.
Text editing is made easier. For instance, you no longer have to double tap to select text. Instead of popup menus, there are new two and three-finger gestures to cut, copy, paste and undo things in iPadOS. Almost any app document can be marked up and shared.
You can import from thumb drives or a camera directly into the iPad.
Apple Pencil lag times have been reduced by more than half.
The keyboard can be minimized to iPhone size to make it easier to type with one hand. You can also drag it around the screen and place it where you want.
I think I'll have to test the beta of iPadOS. :)