Yes, it is called 10, and not 9, for some stupid fucking reason.
I've been using it and I have to say I prefer it over 8, here's the link
http://windows.microsoft.com/en-us/windows/previewI recommend putting the preview on a Virtual Machine for obvious reasons, there are still issues, and there's even a direct Microsoft Feedback app for people to suggest and address issues.
Major Changes
Start Menu instead of Start Screen (Able to change)
New Icons
Virtual Desktops
Direct Search button
New Notification Center
New Animations
Free for Win8/8.1 usersFun fact: I made this thread on Windows 10.