What a fun article!
I work at a nonprofit that refurbishes old computers for students, low income families, and seniors, and I work with old equipment like this (and sometimes older) all of the time. While our customers are always thankful for the service we provide, many of them always feel like newer equipment would run a lot faster/smoother, and they never believe me when I say that it dosn't make much of a difference for things like web browsing and office work (the types of things these computers are expected to do).
The biggest changes in computing over the last 5 years has not been the CPU, but the support hardware. Moving from DDR2 to DDR3 made a big difference in the perceived 'snappy-ness' of computers (especially with systems using onboard graphics). Moving from HDDs to SSDs can make even an old pentium 4HT feel pretty modern because drive speed has been a major bottleneck since the dawn of the PC until now. The difference between the older (but capable) machines they are receiving, and newer computers is almost all in the support hardware. Take a Core2 series processor and pair it with an SSD, DDR3, and a decent GPU and the average person would never know the difference between 5 year old tech and brand new tech. It is only in the size of the hardware, the fans required to cool it, and the power it uses. The disparity in hardware size/power is so great that I fully expect cell phone released 2 years from now to be out greatest competition because modern phones are already almost as fast for day to day use (they just lack the KMV to make them productive). Our computers will still be cheaper, but as our customers are only concerned about up front prices I could see a $100 dock-able phone (with contract) becoming a major problem for us.
on another note;
My old work PC recently died, and so I replaced it with a G2020, 4GB of DDR3, a passively cooled GT610 (would have used onboard video except that I have 2 high res screens), and an SSD. The total cost was ~$275, and it runs so cool that I only have 3 fans in it (CPU, PSU, and case). The old system was a Core2Quad, with 2 HDDs, 2GB of ram, GT460 GPU, and had a total of 6 fans in it. It was loud, it would have been very expensive when it was new (~$800-1000), and it sucked down power like nobodys business. While that old rig (may it rest in peace) would have kicked my new rig's butt in games, my new rig runs circles around the old one for general productivity work (which is what I do at work... honest!).
It is just amazing to me that 5 years later we run on 1/2 the power (or less) with almost passive/silent cooling, and can pick it up for 1/3 the price. I imagine that in 5 more years time this trend will continue and we will run on even less power, run everything except for high end GPUs with passive cooling, and be able to purchase similarly performing equipment for another 1/3 to 1/4 of today's price.