I never thought that it would be hard for companies to move over to Linux but after having delt with personal assistants, professors and students at work, I am convinced that it would take too much to start them over. It is little things, that a power user would never think about that stumps them. They dont know how to use the software. The more important thing is that they have no idea of how the software works from inside, so if something does'nt work the way it used to, it confuses the heck out of them. See the problem is that people are not used to the dynamics of software.
On the actual desktop, it is the person who arranges his equipment (Paper/Pen/Paper weight). Equipment is governed by the laws of nature, and they know how to deal with it, and the laws dont change. On a computer desktop it is different. It is very different. There are many laws at work there. First there is the law of the operating system. Everything is arranged according to the Operating system. If there is a window manager, everything is arranged according to the operating system and the window manager. Then documents are handled according to the laws of the office suite, or whatever else it is that created that document. It is too much to expect normal everyday people to try to learn these new laws over and over again.
So should we keep creating new software, or should we just be improving older software, so that the changes are incremental. Well, according to the users so far, they would rather continue to pay Microsoft to improve the current system incrementally than to switch to a new OS and desktop. They are afraid that there are going to be problems on this new desktop (Linux/KDE/GNOME/etc.) as well. And they dont want to give up one desktop to move to another desktop. The most popular desktops on Linux are those that mimic the MS desktop. KDE and GNOME. Even those that move, dont want to go too far. Imagine moving a Windows user to WindowMaker/Blackbox.
Though if not given a choice, the users will move. As did the users of the Mac. They moved from the old Mac OS 9 interface, to the new Aqua interface in Mac OS X. They moved from an interface that they had been using for years to the new interface that was really good looking but hardly tested. Why did that happen? I believe that the reason is choice. With moving to Linux its a choice. And people are too lazy and too scared to move. But with the Mac the people did not have a choice. Either they use there old systems and dont upgrade, which in this dynamic world is hardly an option for office people. At home it might be, and I wont be surprised if there are people who are still using Mac OS 9. There are people who are using Windows 98. Why not Mac OS 9?
So the conclusion that can be reached is, that, unless the viruses, worms, patches and holes reach a point where the user goes beyond frustration he will not switch platforms. And it must be something more than what happened recently (MSBlaster/SoBig/forgot_name). So, I doubt its going to happen!