It depends on what you are doing. If you love to download and run games off the net, and have all sorts of pop-ups appear all the time from any web sites you visit, Linux will not be good. If you run dozens of commercial programs for CAD, special word-processing, or other specialized applications, the same may be true. If you do general web browsing, view anything downloaded off the net with suspicion, and some general-purpose computing (word processor, spreadsheet, data bases, etc.) then Linux may become a better platform than most people's Windows experience.
The only reason I still keep a Windows environment around (other than my kids) is for commercial CAD applications. What is available on Linux, so far, is not up to par with major applications in this area. I have both electronic and mechanical CAD packages that I still run under a Windows environment using VMware, so I have Windows 2K Pro running on the same CPU at the same time, under the Linux system. I can switch between the two with a keystroke, and move files back and forth. Much better than rebooting, but still a little cumbersome. Win 2K even runs vastly more reliably in this mode than on real hardware!
Jon