For a normal user, Microsoft Windows is already on the top of all Operating Systems.
Now Microsoft has released Windows 8 (x86 or 32-Bit) and (x64 or 64-Bit) – Developer and Consumer Preview Edition.
Though Windows 8 could be used for all purposes as we use Windows 7, Vista, XP etc., but as this is a pre-beta release of Windows 8, so we suggest you to install this version of Windows 8 to a separate partition, for the testing purposes.
Soon Microsoft will release the full and stable version of Windows 8, then you can install it on the production system or workstation.
If you are a developer, then you can create apps for Windows 8 by using the Developer Tools SDK available at Microsoft Website.
As per Microsoft Official Statement, Windows 8 is far better than the previous version of Windows like Windows 7, Vista, XP and all. Windows 8 Chip design is improved a lot, due to which one can experience very nice performance of the computer by using the same hardware as he is using for Windows 7.
To download the Windows 8 Consumer Preview Version (x86 and x64), please visit http://windows.microsoft.com/en-US/windows-8/download.
To download Developer Preview Version (x86 and x64), please visit http://msdn.microsoft.com/en-us/windows/apps/br229516.
Enjoy!