Windows as we know it is an awful platform when it comes to touch, containing far too many tiny user interface elements and requiring far too much precise fiddling. Compare the size (and precision) of your on-screen cursor compared to your finger. Now imagine using something with the precision of finger to carry out tasks such as file management or computer management. Good luck with that.
But modifying Windows itself isn't enough because people use more stuff that just Windows on their PCs. All software installed will need to be touch-capable if people are going to be able to do everything using touch. And it's not just installed software that needs to be customized for touch, but everything users are exposed to – from web pages to Flash applications to driver installers.
Everything will need to be touch-ready, or users will be jarred into having to resort to keyboard and mouse.
I see another problem with Microsoft's Windows on tablets strategy, and it's this. One of the main reasons that people stick with Windows (rather than switch to another platform, such as Mac OS X or Linux) is that Windows offers excellent legacy support.
This means that you can take your brand new computer running a brand new version of Windows, and chances are good that your hardware and software will work on your new system. But when it comes to Windows-powered tablets this won't be the case. Microsoft wants these tablets to be powered by ARM hardware as opposed to the x86 architecture, because ARM is far more power efficient and more suited to mobile devices powered by batteries.
But this power efficiency comes at a cost – the software that you run on your regular Windows system won't work on ARM hardware. Same goes for hardware drivers. That means that all legacy support is gone right from the start.
You'll have a tablet running Windows, but it is Windows is name only. The only software and hardware you're going to get running on it is stuff specifically designed for ARM. Anything else and you're plain outta luck.
Calling the tablet OS 'Windows' creates an expectation among buyers that they will get the full Windows experience, something that could be the undoing of Windows 8. Compare this to how Apple managed user expectation when the iPhone was released. If the platform had been called 'Mac' instead of iPhone OS (only later it was called iOS), then users would have had all sorts of unrealistic expectations for the platform. Expectations that might have killed it before it ever had a chance to really take off.
All this begs the question ... why would you want a Windows tablet if the operating system doesn't offer the full Windows experience? For the life of me I can't answer that question. And to the best of my knowledge and research, no one at Microsoft has answered it either.
But wait, I'm not done. It also seems that Microsoft will limit ARM tablets to software from its own personal app store, much like Apple does for iDevices. But it's highly unlikely that there will be much in the way of a software ecosystem to support the platform.
At launch of hardware, I don't expect there to be more than a few dozen apps available for the platform, and most of those will be Microsoft apps. That's not really going to inspire people to buy tablets. And if tablet sales are weak, developer interest will also be subdued, which results in a vicious death spiral.