Who cares about operating systems anymore? Microsoft’s recent moves toward Linux, along with their emphasis on Azure, should make it clear that OS’s are diminishing in importance. (cf. Red Hat on Azure, SQL Server on Linux, Bash on Windows) Breaking with Steve Ballmer’s (misbegotten) approach to Linux, Nadella’s Microsoft realizes that Windows isn’t the center of their universe anymore (and can’t be considering their inability to convert desktop dominance to mobile devices).
Developer sentiment is another indicator. Fewer and fewer developers care about the OS. OS just doesn’t matter as much in a world of Ruby, Python, Node, MEAN, etc. This trend will accelerate as PaaS providers continue to improve their offerings.
OS’s aren’t going away, but their importance or mind-share is waning broadly.