Microsoft's heyday in operating systems is starting to dwindle down. It may be over a 10 year period, maybe 5, but an irreversible trend has began and nothing is turning it around. Their "Embrace, Extend, Extinguish" mentality worked well throughout the mid-90's and early 2000's, but things change, just as they did with the Dot-com bubble. Windows has a negative connotation associated with it when you ask the general consumer, not to mention that "Windows" to them means Microsoft Office, games, and malware. Are gamers a big enough of a market to continue the domination of Windows? No. How about legacy applications; the ones that look like they're from 1994 but the companies that wrote them have instituted workarounds to get them running on 7 and beyond. These companies that use clunky, old, "legacy" software titles may still be running Windows for now, but this, also, isn't enough of a reason for Windows to continue dominating the desktop in the business. When you consider the cost of the license fees, malware, poor security, NSA backdoors, and other general Windows problems due to its inherently shoddy and poorly thought out architectual design, it's only obvious that it's a matter of time until something better comes along and replaces it. Microsoft started out with VMS, and ended up with a stinking piece of shit (excuse my French).
So here we are, in 2015, and Windows XP just took more of a slice of the pie than Windows 8.x. It's as crazy as it sounds, but it just shows that Microsoft is now finding themselves between a rock and a hard place. It's unfortunate that Microsoft has some real talent inside the company, and it's being squelched by fascist fat cat board members who are slowly driving their operating system division to Zune status. With Wine on Linux, slowly improving and running more and more Windows applications with less errors, it's a strong possibility that one day we'll see it more often on the desktop; the fact that Steam is now supporting Linux is also one big leg up for gamers who don't want to deal with registry woes, .dll files all over the place, and secret keys that can't be removed from the registry for trial software.
Linux also has severe issues on the desktop, and the information can be found by googling the narod.ru site. However, it's about picking which operating system sucks less. I choose Linux, because of the open source nature and control it gives me over my PC. How much longer are consumers and businesses going to put up with Microsoft's dirty business practices? Only time will tell.
This whole idea of unifying applications across devices is a poor idea -- it's another Zune idea. I don't want tablet applications on my desktop, and the experience cannot ever be the same. That's why there's iOS and Android. Keep Windows on the desktop familiarized to those that need it, as it slowly becomes bumped out of its comfort zone and replaced by better altenatives by more honest companies. Let's not forget that Zune used the same type of tiles that the new variants of Windows have, and nobody ever liked tiles. But the foisting machine keeps chugging along at Microsoft, as if the managerial team there are just about vegetables. The proof that MS has serious problems occuring within their walls is leaking out of the company like a sieve, as can be found here: