For the time being the next major version of the Windows client doesn’t have an official label. The Windows 8 moniker continues to be used largely, including by some Microsoft employees, but the Windows vNext, or simply Windows Next are also popular choices.

Now, fact is that planning for Windows 8 had started even before Windows 7 had reached Release Candidate, with the first confirmation offered almost two years ago.

But the latest details offered by the Redmond company are interesting because they offer a little information on the pillars of Windows 8.
Windows 8 / Windows vNext, Work Is Underway, Says Microsoft - Softpedia