SharePoint Communication Sites
The new SharePoint Communication Sites are in the process of being rolled out globally in Office 365 currently. In case you missed it, a couple of weeks ago, on our live SharePoint Power Hour, I did an introductory demo of them.
ALSO, I demonstrated a bunch of new web parts and the improved page editing interface, which gives you the ability to have multi-column layouts.
Here is my corresponding post of all of the modern web parts, which I keep up to date. I edited the post that day after discovering and trying several new ones.