Microsoft has sold 40 million copies of Windows 8 so far—faster than Windows 7 did out of the gate. [Microsoft]
I'm in for 3 copies of the Pro upgrade, which I put on my laptops and parents' computer. The $40 price is a steal.
The superuser features (Hyper-V, VM management, Storage Spaces, Task Manager, improved granularity in file explorer options) and increased speed/efficiency, particularly power consumption, in combination with the crazy low price to have a legit copy could not be passed up. As much as I dislike Modern UI/Metro and a lot of Metro apps, they are easy to overlook with a workaround.
I am sure Microsoft will make an executive decision and re-integrate the Start Menu (for now I am using Start8).
I used to only be semi legit, running licenses issued from my MSDN/TechNet account (technically only supposed to be used for testing/non production environments)...but now fully legit.