Microsoft Isn't Yet Ready to Discuss Windows 8, Surface Sales
"Numerically there's not really much that's interesting to report," Ballmer told The Wall Street Journal in a recent interview. "If you were to call the retailers, they would say, 'Hey, off to a very good start.' We're out of stock a lot of places on touch machines."
For the sake of comparison, when Mountain Lion (OS X 10.8) was released, Apple announced that it roared to 3 million downloads in the first four days. We won't know how Windows 8 compares until Microsoft deems the numbers interesting enough to report.
Ballmer touched on a number of other topics during the interview, such as the fact that Microsoft appears content for the time being to collaborate with Nokia on Windows Phone 8 devices rather than offer its own branded smartphone.