Since early November, when Microsoft announced that no other builds of Windows 10 would be released to users until early January, two different versions actually got leaked, providing us with an early glimpse of a bunch of new features, including Cortana. Leaks usually occur without the owner's consent, but there are cases when some companies release such builds on the market with the intention of stirring up interest in new products and promoting them without actually paying anything.
No matter the reason behind the recent Windows 10 leaks, Microsoft says that “it's not upset” that such a thing is happening because this way it becomes very clear for everyone that users are really interested in its operating system. As if we didn't know that already...
Windows continues to be the number one desktop operating system worldwide, and with millions of people using it every day, it's only natural for interest in new features to be really high.