I believe Linux will become the de-facto standard desktop operating system. Though it’ll take a while for many users to break free from ties to Windows, there is good reason to believe that this day will come.
Consider that the global community is already beginning to rally behind standard document formats. In addition, as browsers like Firefox gain more market share, users are less tolerant of Internet Explorer-only web sites. However, the transition is slow and will continue to be a slow one. Most people will switch away from Windows only when dollars are on the line.