It's been few years since i have committed to use only Linux on my computers. Nowadays, i'm always running on Slackware-Current on all of my work computers (1 laptop, 1 desktop, and 1 workstation). My old laptop is running Ubuntu Lucid 10.04 Beta 2 since i'm using it for testing purpose. My desktop does have Windows XP installed, but i have never boot into Windows for the last 5 months (probably more).
Right now, i'm getting more comfortable with Linux and i think i can start abandoning Windows for my daily activities. I don't play games and so far, games are one of the main reason why users still installs Windows on their computer. The other reason perhaps drivers. Well, so far, i don't have too much problems with drivers. Most recent Linux distributions have a good hardware detection, thanks to the community who developed the Linux Kernel along with Linus Torvalds.
Looking for support? I think the community has better support than asking for official support from Microsoft. Sometimes you have to pay for fast response and the result may not be as fast as the community in Open Source environment. Take a look in LinuxQuestions or probably LaunchPad. They are two example of a very active community, helping others and shares their solutions to those who have problems.
With more and more vendors joined the Open Source community and Linux Foundation, more and more devices and applications gets ported to Linux and in the end, Linux will become more mature than ever and more and more users will migrate to Linux. I do feel that Linux is getting better and better each day.
So, why don't you try to start using Linux from now? Still not sure? Take a look on Why Linux is Better.