According to a set of leaked screenshots of Windows 10 build 10551, it looks like two oft-requested features will be making their way to the browser: synchronized bookmarks and the ability to open a new window by clicking on the mouse's scrollwheel



From Windows Central:

Synchronized bookmarks allows you to sync your favorites and reading list between the mobile browser on Windows 10 Mobile and the desktop client. The screenshots show that the feature is switched off by default. We'll have to wait to see if the feature also syncs history across devices.

You'll be able to launch a new window by pressing the middle mouse button while hovering on the Edge icon, either from the taskbar, Start menu or desktop shortcut.

  Microsoft Edge may get synchronized bookmarks in Windows 10 build 10551