As of Oct 28, 2016, a beta version of WordPress 4.7 has made it to developers for testing purpose. The final version is scheduled to be released on December 06, 2016.
WordPress is highlighting some of the bigger items to test and help they by find as many bugs as possible.
First of all, they have a new default theme, Twenty Seventeen.
This one focuses on business sites. It comes with immersive featured images, video headers, and subtle animations. You can personalise its asymmetrical grid with a custom color scheme and showcase your multimedia content with post formats. This theme works great in many languages and on any device.
You can upload or add an URL of a video which will be displayed in the header. You can still add a header image that will be used while the video loads.
Custom CSS with Live previews.
Now you can do more with CSS and live preview, like tweak the look of something in your theme or from a plugin directly from Customizer.
This feature eliminates the using the theme editor or child theme for customizing your theme.
User admin language.
A user-specific language setting makes it possible to run a WordPress site in one language on the front end and administrate it in another language.
This feature enables the user to select their preferred locale from their profile page.
The backend will be displayed in the user’s individual locale while the locale used on the front end equals the one set for the whole site. If the user didn’t specify a locale, the site’s locale will be used as a fallback.
PDF Thumbnail Previews
If you found yourself in the position that you have a lot of PDFs, but you can’t distinguish between them, WordPress 4.7 will show you a thumbnail preview of all PDF files.
Go on and Test Wordpress 4.7 Beta.
If you are a developer check New Functions, Hooks, and Behaviour for Theme Developers in WordPress 4.7
You’ve found a bug, you can post to the Alpha/Beta area in the support forums.