Microsoft uploaded the Windows 10 Insider Preview build 15002, this release contains numerous improvements for Edge, the Windows user interface, Cortana and various other aspects of the operating system.
Edge for example will get a tab preview bar, a jump list that will let you launch new windows or private windows straight from the Taskbar icon, and preview support for the new Payment Request API for web payments. Furthermore, click-to-run is now the default setting for Flash.
General improvements for Windows include support for tile folders in the Start Menu, improved high-DPI support for desktop apps, and smoother window resizing. Microsoft also made a highly welcome enhancement to the desktop icons, these should now feel more stable and be more predictable when you dock/undock your device or change monitor configurations:
Desktop Icon Placement and Scaling Improvements: We’ve heard from you that sometimes desktop icons aren’t scaled or arranged as expected, particularly after docking/undocking your device, working with monitors that have different DPI, or projecting your monitor. We want users to feel that desktop icons are stable, scaled properly, and move predictably when changing monitor configurations, so we’ve made changes to how this logic works in order to address your feedback. Now when you change your multi-monitor configuration, dock/undock your device, project your display, add or remove monitors, or otherwise make changes that affect the icon scaling, you should see an improvement in how the system adjusts the layout of your desktop icons. Try it out and let us know how it goes!
It's too much to cover everything so you can check out the full list of improvements at the Windows Blog. Here's an example of the new tile folders in the Start Menu: