Within the last year, I've become quite familiar with Linux (Ubuntu, Suse) and Mac OSX. That means: I already knew Windows, of course, and "familiar" means I can set them up for myself and configure everything just like I want.
Because of this administrator knowledge, I also had to set up some PCs for friends and family members during the last few years ("had to" means: no one else could be found who could help - other geeks will know that dilemma). Of course those machines all run with Windows XP because that's standard for normal PC users.
As I gained experiences with all those operating systems and observed those Windows-users who, basically, rely on me to keep their machines running as expected, I noticed that there indeed may be a turning point in sight: I consider not giving those people Windows the next time! Why?

1. The Operating Systems get more and more comfortable. Mac OSX is really nice and top-rated by most of its users. Linux distributions like Suse and Ubuntu are really close to be usable for a broad userbase (in fact, I came to Linux last year and getting it installed and configured is not such a geek-honour like it was 5 years ago).
2. More applications are available on all platforms. There are projects like Firefox, Thunderbird or OpenOffice - which is really usable for people with normal demands. And there are more and more applications that are available online.
3. 1) and 2) are product of the hard work of many people over the last years. Those things were described years ago, but I feel that they are just about becoming really close to reality. Also, 1) and 2) are more important for the administrators, those people like me who set up systems for friends and family. The user side argument is: There are a lot of users who basically do not install anything special. They just surf the internet and write emails and documents and that's it. Those users, mostly people over 40, are a lot of people, a huge part of "my" machines are operated by those. They expect that "the machine just works". If there is something broken or not working as expected, they'll be calling me anyway. Then, why the hell shouldn't I install on their machine what I know to handle best? That would be reasonable. All they need to know is where to find which button. Also, with Linux, I could avoid the legal/illegal Windows copy - question (which is getting more important in a few month as it seems)
   

If already I, not too professionally experienced with administering operating systems, think about this - that turning point seems to be in sight.