Yep, you guess it, it's a massive but! It will be unavailable to the average human being until October.
Only yesterday, Microsoft completed Windows 8.1 it has been seeded to manufacturers. But us less important must wait until October 18th. Strangely, MSDN and TechNet subscribers won’t get an early look in despite the face they ARE developers, but that's just how Microsoft rolls I guess.
The reason this matters to technological society is this means Microsoft get another shot at getting into the glorious tablet market as this will only be available for tablets. This also seems like Microsoft are slowing down the whole PC market thing as tablet's are supposedly taking over the pc (I personally disagree).
So yeah, that happens. Windows 8.1 in 2 months