Microsoft has already released the Windows 8 Release Preview. Anyone can download it for free and install it. Be warned though that you will have to purchase a license to continue using it after the official Windows 8 release.
Windows 8 is built on a core of Windows 7, and is designed to look and operate much like the Windows phone operating system. It is a drastic change from Windows 7, and is more deeply integrated into the internet. Windows will also have an App store for it. The new Metro Interface will look like tiles on the screen.
Windows 8 will be released “sometime in the fall”