We all knew that Windows 8 would be ARM compatible but up until now the details of exactly what the move might entail have been sketchy.

Microsoft's Steven Sinofsky has now come clean with all the official details, solving a few mysteries and confirming several ARM-based Windows murmurs.

The big news is that Windows on Arm (or WOA) will be treated as a separate entity, much like Windows Server, Windows Embedded or Windows Phone, but with the remit of being seamless across the Windows 8 experience.

This means that, out of the box, you'll be getting the same (at least on the front-end) experience that you would with a fully fledged Intel or AMD x86 Windows 8 PC. So that means access to the Metro style apps (apps can be written for dual architectures), hardware accelerated HTML 5 features, the full Windows desktop behind the tiles and the same desktop Office applications including Word, Excel and PowerPoint (codenamed Office 15).

Sinofsky says Microsoft has been working closely with the big ARM players including Nvidia, Qualcomm, and Texas Instruments. We've already seen Nvidia and Qualcomm demo Windows 8 tablets and the aim, according to the Windows bossman, is to have ARM Windows 8 products landing at the same time as PCs designed for Windows 8 on x86/64.

The public will be able to get their hands on Windows 8 on 29 February when the x86 Consumer Preview goes live. An invitation-only WOA limited test will be taking place between now and Windows 8 launch day as well.

"These devices will be running the same branch of Windows 8 on x86/64 as we release broadly at that time," said Sinofsky. "These are not samples or hints of forthcoming PCs, but tools for hardware and software engineers running WOA-specific hardware."

Over in Vegas at CES, Pocket-lint was given its strongest indication yet that Microsoft will launch Windows 8 in October. Janelle Poole, director of public relations of the Windows Business Group, told us: "We haven't talked about the release date and we generally don't. We are talking milestone to milestone, so for us right now we're talking about the next milestone being the consumer preview happening in late February. 

"One of the things that I think is a good guideline though, is we've always said that Windows releases come round about every three years and this year will be three years in October since we launched Windows 7. So I think that's a good guideline to consider."

2012 is shaping up to be a very big year for Microsoft.