Microsoft has released a new version of its Windows 8 OS, the new version is Windows 8 Enterprise and it comes with a 90 day trial for both 32-bit and 64-bit versions of the OS.
The Windows 8 Enterprise 90 day trial version is designed for developers and IT professionals, of course anyone should be able to try it out, but this version can not be upgraded to the full version of Windows 8 when it is released in October.
The Windows 8 Enterprise 90-day evaluation is available to developers to build and test Windows 8 apps on the final version of Windows 8. After installing Windows 8, go to the Windows Dev Center developer downloads page to install Visual Studio 2012 and related tools to build Windows 8 apps.
You can find more information about the Windows 8 Enterprise edition 90 day trial version over at Microsoft.
Source The Verge