Confirmed! Windows 8 Release Preview is scheduled to be released the first week of June.
Microsoft made the announcement at the Windows 8 Developer Days conference in Japan. When the final version of Windows 8 will be released? This still uncertain, but knowing that everything is on track, we could expect a final version by October, 2012.
What is features are included in Windows 8 Release Preview? That’s to be announced, but you can get a glimpse to what is coming in this article — Compare Windows 8 vs. Windows 8 Pro vs. Windows RT vs. Windows 8 Enterprise [Feature-by-Feature].