I assemble my own computers and I am way right of M$. I can setup a computer that runs linux and have it do anything windows can do for free. Sad though, I really can't make a living doing that. Just about everyone wants to use Windows.
'Just about everyone wants to use Windows'
It's more like everyone is to lazy to install a different OS.
I think Linux is for people who REALLY like to get into computers and tweak under the hood, Mac is for people who do a lot of creative stuff, and don't want to get under the hood. BTW, I noticed something that MAY indicate M$ may need to start worrying about Apple again. Adobe is developing a new program called Lightroom. It's aimed at professional photographers, and they're developing it for the Macintosh platform before they develop it for Windows. That may just be because Vista won't be coming out until next year, but when was the last time a major software developer produced a multi-platform program for the Mac first? IMHO, Linux won't take off unless the peripheral manufacturers start developing drivers and the major software manufacturers start making Linux platform programs. For example, the Epson 2200 I use requires different ICC profiles for different papers. Epson makes the profiles that will plug into the Mac and Windows platforms, but I have no idea where I would find an Epson Photo Luster ICC profile for a Linux based printer driver, or where I would find an Epson 2200 print driver, for that matter. The Canon 1DMII RAW image converter is necessary to convert images from the Canon RAW format to TIFF or JPEG for editing. Canon makes it for Mac and Windows, not for Linux, and it's proprietary.
I think Linux will be relegated to tweakers and guys that run primarily web-centric operations unless some corporation starts persuading a LOT of people to support it.