Windows 8 may see a commercial release in August 2012 followed by Windows 9 in November 2014.
Monday brought reports of a leaked Microsoft road map revealing an August 2012 commercial launch schedule for Windows 8. Prior to that, the beta will reportedly arrive during CES 2012 this coming January along with the WinStore Beta, an online market <ONM> community technology preview (CTP), and the first "Tango" update for Windows Phone. Windows 9 is even slated for a late 2014 reveal.
According to the roadmap, the Release Candidate for Windows 8 (RC) will roll out at MIX 2012 along with the online market beta and the Kinect commercial SDK -- "Apollo" for Windows Phone is also expected to be revealed. By the time E3 2012 rolls around, Microsoft will reportedly unveil the Xbox 360 SDK for creating apps, the Apollo SDK for Windows Phone and third-generation Kinect games. The Windows 8 RTM build is also expected to be released in June 2012.
Once August 2012 arrives, Windows 8, the online market, Windows Phone 8 and the Xbox (App) Store will launch if all goes according to plan. Then in September during BUILD 2012 Microsoft will offer a Windows 8 product upgrade developer preview and announce something called <OSN> along with the XAML+XDE platform.
On the Windows 9 front, a developer preview is expected to go live during BUILD 2013 followed by a Beta during CES 2014. A Release Candidate is slated to arrive during MIX 2014 followed by the RTM build with Internet Explorer 12 during BUILD 2014. It also looks like Windows 9 Mobile will also make its debut, as both the desktop and mobile versions will go commercial in November 2014.
To see the full roadmap, head here. As always, take this forecast with a grain of salt because (1) things change and (2) there's no official confirmation from Microsoft.