Microsoft announced next Windows OS on ARM

The company also confirmed that Intel and AMD were working on low-power SoC designs that fully support Windows, including support for native x86 applications.
“With today’s announcement, we’re showing the flexibility and resiliency of Windows through the power of software and a commitment to world-class engineering. We continue to evolve Windows to deliver the functionality customers demand across the widest variety of hardware platforms and form factors,” said Steven Sinofsky, president of the Windows and Windows Live Division at Microsoft.
Although it is well worth noting that the the company represntative didn’t mentioned the vesrion of the next gen. operating system but we can only speculate it to be Windows 8 multi-platform.
Mr. Sinofsky refused to give a timescale for when the next release of Windows will be available, but commented that “24-36 months between releases seems about right.” Windows 7 was released in October 2009, suggesting that the release will come between October 2011 and 2012.