but with the http base
for web apps, any clientside processing needs to be redone on the server side, to protect the server from exploitation. So the traditional definition for client/server needs to alter to remove the client side processing from it as a requirement.
I'm not arguing against the idea that web apps are the wave of the future, but your "Anything capable of I/O over a network wire could be considered to be client/server" sounds like a better definition for client/server because of the trend that spawned the blog post. It's a more "basic" ( sic ) definition.