This is very significant because it has signaled a shift from a time where Operating Systems was once a major revenue stream. Very interested to see if Microsoft will follow suit.
"Very interested to see if Microsoft will follow suit." And what? Make it up in volume? Unless Microsoft's Surface sales take-off, they can't afford to give Windows away for free apart from what are essentially service-packs like the 8.1 update they just released.
Just chiming in conversationally (not refuting anything), but Windows original ascension was entirely based on piracy -- Microsoft did nothing to stop home users from thieving Windows as it lubricated its use for business (and business could much more easily be convinced to spend, if not at the outset, once the infrastructure was in place and they suddenly worried about a disgruntled employee turn them in).
And of course, Microsoft knows (and controls) the ecosystem more than anyone. Microsoft should be able to monetize users beyond just the operating system, but they are proving totally incompetent at doing that with home users.