An interesting stat that can be seen on Amazon’s site is that 75% of people who bought OS X 10.6 also bought the Windows 7 upgrade (figure 1). Seeing Microsoft has 93% of the OS market share (figure 2) and Apple has 4% of which Microsoft will also have 3/4 this Microsoft will have 96% of the total OS market share. This is huge and indicates that many OS X users are keen to use Windows 7. I think this will lead to the eventual loss of market share of OS X compared to Windows 7 as more OS X users realise first hand that Windows 7 will be an even more solid alternative to OS X. I would also say this % will actually be a lot higher as this number only includes people who have legally acquired the product.
Figure 1. Amazon OS X listing
Figure 2. OS Market Share
Interesting to see in Figure 2 is that more home users are running Windows Vista compared to Windows XP which seems to also confirm that most business are lagging in deploying Vista (probably because they are waiting to for Windows 7).