Apple and Google have been systematically killing PC sales at Microsoft's expense, and the situation for Redmond is nearing Defcon 5. It's not even necessary to cite numbers to support that assertion; all you need to is open your eyes and look at what people are carrying around in their hand, or in their backpack.

Look at the checkout lines at Best Buy and see what people are buying. Apple has technogeeks camping outside of its stores at 1 a.m. waiting for the next cool new product to be released. When is the last time Best Buy had people waiting outside to buy a laptop loaded with a new copy of Windows?

The problem for Microsoft is now two-fold, because it's not just the technogeeks in the consumer segment it's losing. It's also poised to lose ground with the average business professional. IT shops are being bombarded with zillions of iPhones, iPads and Macs, and in some cases businesses are using alternatives to Windows as a foundation element of their key technology initiatives. People love Apple's stuff because it's fast, it's easy to use, it's easy to carry, and it's easy to mix business with pleasure.

[ Read Windows 8 Beats The Mac, Appsolutely. ]

Microsoft's answer to catching up and becoming cool again? A completely revamped OS with a consistent look and feel that can run on PC's, tablets, or smartphones. Sounds like a great idea. The problem? Execution. Nearly everyone's first impression of Windows 8 is confusion. In fact, every random business professional that I've casually shown Windows 8 to looks at the new user interface like it's like a Rubik's Cube. Put a three-year old in front of an iPad and he'll be downloading apps and movies in two minutes flat.

No one will argue that Microsoft has some of the brightest and most talented developers on the planet working for it. And 12 months from now, we might all be wishing we bought Microsoft stock if the Surface tablet turns out to be the perfect fit for the mobile professional who needs to run Microsof Office natively on a portable device. But what if Windows 8 is a complete disaster? What if it never catches on, like Vista? And most importantly, what are the implications for IT pros if Windows 8 blows up in Microsoft's face?

What will happen if the enterprise shuns Windows 8? It will simply be Windows Vista history repeated, and enterprises will simply not deploy Windows 8 to business users.

By all accounts, Vista was a colossal disaster that brought no incremental value, and most enterprises threw Vista in the garbage can. The idea of a consistent OS across mobile, tablet and PC is a great concept. But in the real world, user acceptance is a big deal, and the initial feedback from real users tends to be less than stellar. We all understand that change in inevitable in this business, but Windows 95 was a drastic departure from Windows 3.1, and I don't remember the backlash being so vocal when Windows 95 went gold.

IT pros can take solace in one inevitability: no matter how much market share Microsoft loses on the client side, Windows Server 2012 and beyond will continue to thrive. There are a lot of cool new features inside of Windows Server 2012, and there are hundreds of thousands of IT pros that have their careers and fortunes superglued to a copy of Windows Server. And in many respects, Hyper-V is catching up to VMWare, so if anything, Microsoft is further cementing its dominance in the data center.

iOS and Android devices can and probably will continue to take market share on the client side as business professionals transition from bulky devices running Windows to other alternatives. But at the end of the day, enterprise IT will continue to run Windows Server, as we discuss in our report, "Windows 8 Survival Guide: Server 2012". IT will continue to use Exchange, it will continue to scale out SQL and Sharepoint environments, and it will continue to upgrade to the latest Windows Server OS, because really, what other option is there?