Microsoft has just pulled the trigger and launched the Windows 8 Consumer Preview and it's ready for download and your testing now.
Windows 8 Consumer Preview Setup will check to see if your PC can run Windows 8 Consumer Preview and select the right download. Setup also features a compatibility report and upgrade assistance. Built-in tools for creating an ISO or bootable flash drive are available for some previous versions of Windows (excluding Windows XP and earlier). You can find system requirements and additional information in the FAQ and in the links on this page.
Note before you download: Windows 8 Consumer 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. If you decide to go back to your previous operating system, you'll need to reinstall it from the recovery or installation media that came with your PC.
Go and grab it here if you are interested.