Windows 8 isn't due out for consumers until October 26, yet it appears a final version has already been leaked out onto the web. Even early access people, those with TechNet, MSDN, and other subscriptions and contracts don't get access until August 15 at minimum, so if this a true version, it had to come from a hardware manufacturer.
"It looks like our first leak has occurred, as Windows 8 Enterprise N has appeared on torrenting sites and has been confirmed by several that it's the real deal," said winbeta.org in a post earlier today. Winbeta.org is a site which follows Windows betas. They throw out a disclaimer: "Remember, we are yet to confirm this as real or fake."
Of course, Microsoft would encourage you not to download a copy for several reasons. One, they have no control over what's contained in the package, so it could be packed full of malware. Two, they'd much rather sell the operating system to you than have you get a copy for free. Microsoft declined to comment on this issue.