Microsoft has announced the release date of Windows 8 as the 26th October. There will be three versions, Windows 8, Windows 8 Pro, and Windows 8 RT for ARM based tablets like their recently announced Surface tablet.

If you want to take a look at Windows 8 prior to the official released date there is a Release Preview available at the link  below.

http://windows.microsoft.com/en-US/windows-8/release-preview