According to some source Microsoft is actually on track to release to manufacturing all Windows 8 versions by April 2012. This contradicts the earlier revelation:
"Microsoft's goal with Windows 8 was to release to manufacturing (RTM) its next Windows release around Q2/Q3 2012, after two beta releases, plus various preview/RC drops. Also note that the plan was to RTM Windows 8 for x86, Windows 8 for ARM/SoC (system on a chip) and Windows 8 Server all at the same time."
"The source also indicates that Microsoft's latest game plan is to deliver a beta build--not a pre-beta or preview -- of Windows 8 around the time of the Build conference in mid-September. This allegedly will be the one and only Windows 8 beta. In January 2012 or thereabouts, Microsoft will deliver a final Release Candidate (RC) test build of Windows 8, the source said. And the next and final milestone after RC will be RTM," reports MJFoley.
There are a few things to keep in mind here. So far, the Windows 8 team at Microsoft has said nothing about where it's at on its road to RTM. (Thanks to various leaks, we know they've basically finished the internal Milestone 3 build.) The only thing the Windows 8 leaders have offered, guidance-wise, is that Microsoft expects to deliver the final version of Windows 8 24-36 months after Windows 7. It was never clear whether the Windows brass meant two/three years after Windows 7 RTM'd or shipped, and they never clarified. (Windows 7 RTM'd in July 2009 and "launched" in October 2009.)
[Via: All About Microsoft]