Microsoft has made a lot of noise about its next operating system, Windows 8 being compatible with ARM processors. At this point in time, I really do not think Microsoft has a clue as to how slim down their next operating system to fit into lower powered machines. But they want us to know they will be there. They are really telling us, to wait and they will provide us a Windows solution in the tablet space too. Don't migrate, we will be there soon. Why is this so important to Microsoft?
No one really loves Windows, and to be fair no one really loves an operating system. It is what we can run on the operating system which makes it important. I am not a power user. The most important software for me is a office suite, a web browser and a photo editor. For 2010 I actually use three different operating systems. Since I migrated to OpenOffice seven years ago, which is compatible with Windows, Mac OS and Linux I get the same functionality and interface on my word processor and spreadsheet creator whatever platform I am on. I use Google's Chrome as a web browser on Windows and Linux, and kept Safari on the Mac, but going between the two browsers is no big deal. The main difference is where the Google search box and bookmarks are located. For photo editing, I use Kodak's Easy Share software and Paint.net on Windows, Shot Photo Manager and the GIMP Image Editor on Linux and iPhoto on the Mac. Notably, all the software I use is free license, except for iPhoto, but that came pre-installed in my MacBook Air. But like I said, I am not a power user.
For others, whether running business software or an avid gamer, sooner or later they will want to install something which only runs on Windows. Windows having have and held the biggest market share in the desktop and laptop space for more than a decade, most software is developed for it. It is the software in the market which maintains Windows dominance, and not Windows itself.
Microsoft has sallied forth Window Phone 7, despite the nearly incredible odds this platform faces. And they will launch a tablet compatible OS too. They are defending their turf. Mobile phone operating systems became tablet operating systems, and I suspect will find themselves in small netbooks soon too. I would be in the market for a 11.6-inch Apple A5 Chip. They could use the extra space for a really big battery and give us 15-20 hours of real world battery life. I can be equally productive with iWorks.
So as more and more App's are designed for iOS and Android, and as smartphones migrate from pocket computers to handheld PC's and tablet get more powerful, you may come to realize all the software you need run on iOS or Android... and you may realize you do not need Windows anymore.