An interesting article here, proposes that its entirely possible that Linux will become the Number 2 desktop OS just behind Windows some time soon, possibility in the next year or so.
"The predictions come from IDC and they reflect the fact that in the last few months Linux on the desktop has become a reality. It is now possible, for example, to buy a Linux-based PC (running LindowsOS) from Evesham. In the United States, Wal-Mart sells machines based on Lindows, Mandrake Linux and others. But though Linux may have its foot in the door, taking the next step to becoming a mainstream success is proving a more difficult proposition..... IDC expects that Linux will become the No. 2 desktop OS in the next year or two, surpassing the Mac OS, and will continue to hold this rank for the remainder of the company's five-year forecast....."