The pre-beta of Windows 8 has been released for public download. This early release is intended for developers and carries no guarantee of stability or functionality. The idea is that developers get a flavour of the Windows 8 environment and can start developing apps ahead of the official launch (or even beta launch). It’s offered in 32 and 64 bit, bundled with or without the software development kit bundle.
Microsoft make no promises of releasing any of the features included in the pre-beta.
For those interested you can download the ISO from the Microsoft Developer Network Site here.