Microsoft has released Windows 8 Release Preview ISO images
Windows 8 Release Preview ISO files (.iso) are provided as an alternative to using Windows 8 Release Preview Setup. If you are on a PC running Windows and want to install the release preview on another partition, another PC, or a virtual machine, we recommend you download Windows 8 Release Preview Setup and use the built-in tools for converting an ISO image into installation media, such as a DVD or USB bootable flash drive. You can find additional information, including a list of supported upgrades, in the FAQ.Windows 8 Release Preview ISO images
Note before you download: Windows 8 Release Preview is prerelease software that may be substantially modified before it’s commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here. Some product features and functionality may require additional hardware or software.
