Android O adds notification dots to home screen icons, sort of like iOS but without the number count. What's interesting is, you can long press on the icon to bring up the pop-up list function, and the notification will actually be there for you to act on. Pretty interesting, and looks simple, clean, fast, and is accomplished without the need for a complex/expensive pressure sensitive screen.
It's demonstrated right at the start of The Verge video:
The Verge video also talks about Android security and how Google is bringing that front and center. I know this concerns some people.
MKBHD does a decent run down of the new features, too: