Slowly but surely, Windows 7 has been increasing its market share until finally, in September, it outpaced Windows XP as the most popular operating system worldwide.
Then only a month later, Microsoft released its successor, Windows 8.
As XP approaches the end of support, most folks will be upgrading, one way or the other. For many, the big decision is whether to go to Windows 7 or jump right into Windows 8. That will largely determine how quickly the latest version of Windows starts to see its numbers tick up.