Version 4.8 will be the first major release for WordPress around June 8, 2017. Some of the upcoming features coming in the new WordPress.
Text Widget has a Visual Editor
By default WordPress comes with a plain text widget. This widget contains a simple text box where you can add text and HTML code, now the new text widget comes with a simple visual and text editor like the one then you edit the post.
It will be much easier to add links, create lists, or make text bold / italic without any help of the developer or learning html code.
New Image Widget (image to the right)
WordPress 4.8 will introduce an image widget which will allow users to easily add images into the sidebar. You will be able to upload an image right from the widget or select any image from the WordPress media library.
Clicking on the select image will open the WordPress media uploader popup where users can upload or select an image. After inserting the image, users will be able to see a preview of the image in the widget area.
New Video Widget (image to the left)
Similar to the image widget, the new version will introduce the Video widget. It will allow users to easily upload videos to their sidebar or display any video from YouTube, Vimeo, or any other oEmbed provider.
Add the URL of the video you want to embed and then click on the ‘Add to widget’ button. The media uploader popup will disappear, and you will see a thumbnail preview of your video inside the widget.
And some improvements on the back side, the update has improve significant parts of the WordPress core, soon we will know more.