Doctor Syntax: "At some point H/W manufacturers may either move to Chromebooks or the like or get together to fund development of an alternative OS, maybe based on Linux, BSD or possibly ReactOS which they can control."
I've tried Chrome, and it probably has its place. But I think Android N may be an even stronger contender. I'm sure there's a reason Google has been adding desktop features like windowing and mouse support. Many consumers would probably like the idea of running the same OS - and apps - on their desktop as they do on their phone or tablet.
This is probably the 'nightmare scenario' that Microsoft tried to forestall with its awkward Continuum feature. Unfortunately, it's a lot easier for Google to make Android run comfortably on generic PC hardware, than for Microsoft to make Windows run on its own smartphone hardware. Still worse (for MS), Google can bring along its entire base of existing Android apps, while Microsoft could only make the stunt work for a tiny number of new-fangled UWP apps.
Likely future: for casual users, Windows Home gives way to Android N; for power users, Windows Pro is replaced by GNU/Linux. PC games shift to SteamOS, and the console world remains divided, with Steam Machines making gradual inroads as the economics of the open, generic PC architecture erode the cost advantage of proprietary games boxes.