Windows 7 is good for fast, newer computers, however, what about your business computers? The economy has forced business to stretch the life of their old machines or to purchase lower-grade new computers. Linux is a perfect candidate. Linux offers software compatibility support where believe it or not some companies have not upgraded their software to be compatible with Windows 7! Windows 7 also takes a great deal more amount of memory and CPU speed. With Linux you can run your favorite Windows app in a virtual machine anyhow and not loose any of your favorite programs from XP.
As for the home user, there will most likely be a split. With the current environment a large population will only upgrade computers as they need to due to component failure. The technology has not advanced enough to warrant considering 5+ year old XP machines obsolete to the point of a necessary replacement. Home users are growing wary of being forced to upgrade both software and had ware at the whim of Microsoft.
This does leave the techno crowd and those who love to have the newest and best and have the disposable income to spend but this population has been smaller as of late. This is also the population where Linux and Mac tends to be competitors. Before you pay a dime for Windows 7, try a Linux desktop distribution. If you don’t like it, what’s the worst that’s going to happen? You spent no money other than for a burnable CD or DVD, a little time, and you just have to wipe your disk again before installing Windows 7.
Windows and Mac OS are like a toy car that you buy off the shelf and play with. Linux is like the same toy car made out of Lego You can play with it as it comes or you can remove and modify components (or the whole thing) and tailor it to your liking. To illustrate the point, Linux comes with many different choices of window managers, desktop environments, file managers, package managers (packages are what Linux calls programs), etc. The idea is to be able to tailor a distribution to exactly what you need and like.
There's nothing in Windows 7 that Linux can't do, and in most cases, do it better. Linux machines are quicker and more efficient. Linux desktops are more innovative and less static. Linux apps are more powerful, cheaper and less partisan, and Linux security has never been better. But best of all, we have complete control over the future of Linux, as opposed to allowing Microsoft to run roughshod over us in forcing the upgrade to Windows 7.
Don't forget that for any operating system, no matter how similar to to a commercial OS it might be, there is a learning curve involved. This is especially true of the software available and how to download it Generally software is downloaded from repositories using a package manager included with your distro. By and large you will not find commercial software in repositories, but will find thousands of free open source equivalents. Most of these are as powerful as the popular commercial ones, but require that you familiarize yourself with them. Take some time to do this and you'll be a really happy Linux user.
So, you think you may want to dip you toe into the Linux waters at this point? Ok, I have a couple of suggestions.
Try a Linux "live CD" first. Most Linux distributions have live (aka bootable) CDs that let you actually use the Linux OS of your choice directly from the CD. It will run slower, due to running from the CD drive, but it will give you a real feel for the Linux OS you may be contemplating. In addition, it will let you know, before you actually install it to your hard drive, whether or not it can support all your hardware. That way, you know beforehand exactly what to expect!
Even if you never get further than a Linux live CD, you will want to keep it around. Linux live CDs make extremely good disaster/recovery tools. One of my favorite uses is to clone my Windows XP partition. Just boot the live CD and clone one partition on one drive to an identical partition on another drive. A good bootable Linux CD like Knoppix should be in everyone's tool box, even if they're a die-hard Windows user.
Here's another last bit of advice. I recommend dual booting only one absolutely safe way: buy a second hard drive and install Linux on it. You can even use a USB thumb drive for this! This is also the easiest way to get into Linux. No tricky hard disk-partitioning to worry about. No way to mess up your current Windows install. Absolutely the easiest and safest way.