If Linux works on your system I agree with you entirely. Unfortunately this is not always the case. Linux's biggest hurdle towards mainstream adoption is compatibility, especially with newer systems. This is not the fault of the Linux developers. Hardware makers provide windows and mac machines with all the necessary drivers to get heir hardware working. However, with a few exceptions, they don't do this for Linux and the Linux community has to create these drivers themselves. This means that often a new piece of hardware doesn't have a suitable Linux driver for quite some after its' release. For example, several months ago I got a new laptop pretty much as soon as it became available that came with a new Intel AGN wireless card. When I first received it none of the Linux distributions I tried recognized my wireless card correctly. Only now, 8 months later, do I think most distributions have it working properly. Often for an issue like this there may be temporary fix released earlier but it requires some more advanced tampering on the user's part.
That all said, Linux's compatibility problems would be completely solved if Linux were more popular. The reason hardware makers don't make drivers for Linux is because Linux has very few users relative to windows or mac. There are many reasons why in coming years Linux will become more popular which will naturally help overcome this obstacle. Just look at how much better the nvidia and ati drivers have gotten recently. I have no doubt that this happened due to an increased demand for it.
The better Linux is obviously the more people will use it and you've already shown how great it is in many different areas and how improvement is accelerating. A recent improvement in the usability of Linux which you failed to mention lies in the ability to run “windows-only” programs within Linux. In the past, if you needed a specific program designed to work only in windows you would be forced to keep windows on a separate partition and boot into it when necessary; a very bothersome process, especially if it's a program you use frequently. Now, you have two alternatives. You can either use a program like WINE or use virtualization software. WINE which stands for “Wine Is Not An Emulator” is an open-source implementation of the windows API which uses Linux equivalents of windows components to run programs. The goal is to be able to click on an executable and have it run seamlessly inside your Linux environment. WINE's compatibility still isn't great and many programs won't work perfectly or at all but WINE is constantly getting better. Alternatively, Virtualization software creates a virtual system for you to install your OS. It allows you to run multiple operating systems concurrently on the same PC. Basically, if you have a windows installation disc you can have your windows installation sitting in a window inside your Linux environment and access it with the click of a button. Any program designed for windows should work inside the virtual installation of it.
Also, you mentioned Linux's improved media support but didn't mention its' improved game support as well. Unfortunately many games aren't designed to run natively in Linux. Luckily, WINE is designed especially with games in mind and works with whole bunch of them.
Another thing that will accelerate Linux's popularity is the increased popularity of open-source software in general. More and more open-source projects are starting and more and more business are using them. Due to this Open-source software is also getting a lot more media attention. If I had thrown around the term open-source to my friends a few years ago I think I would have received many more confused faces then I would today. Both in the business world and in the public eye open-source software is gaining legitimacy.
I agree that it is a very exciting time for Linux and the improvement just keeps accelerating faster than any other OS. In my opinion, the only real downside for the home user is compatibility. Luckily, Linux is free and easy to try. Just download a live CD, pop it in your drive, there's no need to even install it , if it works fine you got yourself a new Linux box, if it doesn't, throw it out and no harm done; you can try downloading a different distribution if you like. The support you get from the community is usually very good and will help you overcome any problems that you might encounter. If you're really paranoid though you can always pay for support and it will still be a lot cheaper then paying for windows or mac. My distribution of choice is pclinuxos. The one thing Linux will always have over it's competitors is choice.

Great article. In time Linux will get the appreciation it deserves.