Windows 8 RP is now live.
Here is the link to the ISO files: http://windows.microsoft.com/en-US/windows-8/iso
64-bit (x64) (3.3 GB) Sha 1 hash — 0xD76AD96773615E8C504F63564AF749469CFCCD57
32-bit (x86) (2.5 GB) Sha 1 hash — 0x8BED436F0959E7120A44BF7C29FF0AA962BDEFC9
Windows 8 RP Setup: http://windows.microsoft.com/en-US/windows-8/download
Enjoy!