According to reports, Microsoft's next generation operating system, Windows 8, will be released in 2013, and a beta during PDC 2011 in September this year.
"The public might get its first look at the Windows 8 code at Microsoft's Professional Developers Conference in September and a release sometime in 2013 (unconfirmed). Windows 8 might not even be the label for the operating system, since Microsoft refers to it as "Windows Next." This analyst also claims that the company will also release the client and server operating systems at the same time. Since Microsoft is known to eliminate planned features, we should not rely on seeing all those neat features we see in screenshots and leaked builds of Windows 8."
Here's the current state of Windows 8 -- "the latest internal winmain build of Windows 8 is 7995.0.110429-1832 (as of May 02) according to our internal sources. This build is still very buggy and has a tendency to show numerous BSODs. The Black Screen's are also incomplete but are indeed real and we will be seeing them as a replacement to the old Blue Screen."
The activation process has also changed in recent builds. Previously, all builds of Windows 8 had a universal key that allowed for unlimited activation. As of now, all new builds are required to use unique key which is exclusive to an employee of Microsoft or a verified tester.