The main idea behind it was that the desktop application are slowly (or rapidly) dying since google and other companies started making typical applications like mail and office suites with web technologies. I agree with his point in a way, but i think that we have a long way ahead of us, cause in my opinion there are areas of applications that web technologies just cannot help, such as computer games.
I dont think that web technologies are a Panacea for all our problems. Its like trying to take an aspirin to cure cancer.
Reading Mr. Graham's article i found two of his comments true and rather enjoyable:
The last nail in the coffin came, of all places, from Apple. Thanks to OS X, Apple has come back from the dead in a way that is extremely rare in technology.  Their victory is so complete that I'm now surprised when I come across a computer running Windows. Nearly all the people we fund at Y Combinator use Apple laptops. It was the same in the audience at startup school. All the computer people use Macs or Linux now. Windows is for grandmas, like Macs used to be in the 90s. So not only does the desktop no longer matter, no one who cares about computers uses Microsoft's anyway.and ...
Microsoft's biggest weakness is that they still don't realize how much they suck. They still think they can write software in house. Maybe they can, by the standards of the desktop world. But that world ended a few years ago.Maybe someone has to visit Greece and see the Vista mania here ... and enjoy the great contract between microsoft and the public sector of Greece. I dont know about the US ... but microsoft seem very alive here :(.
btw i use Mac OS X and Linux for work and Windows only for gaming ... :). Flirting with cedega for some time now ... time will tell, sooner or later, time will tell.