As we mentioned earlier today the expected availability of the Windows 8 Release Preview has finally occurred and is ready for immediate download.
If you are an MSDN or TechNet subscriber you can find the download there. If the new downloads are not showing the files just search for release preview to find the downloads.
As for everyone else you can grab it from Microsoft’s Windows 8 Release Preview download page.
The download weighs in at 3.3GB for the 64-bit version and 2.5GB for the 32-bit version. It looks like all the public downloads are using the same serial key for installation just like they did for the Consumer Preview however, it is a different key so make sure you write it down.