I'm not so sure about the format of Common Myths About Web Design. I haven't been hearing most of these myths, at least not since the late '90s. The only reason I'm linking to the article is that it captures some of the shift from web pages (static, html, browser-bound) to web services and networked applications, which require a different design perspective. Ironically, this "new" perspective may borrow more heavily from pre-Internet software development methodology.
We're seeing that shift in our interaction-design work these days -- we used to be able to storyboard a site by thinking in terms of building and connecting discreet pages of content. It was quite predictable because pages could live in a pre-determined structure and you'd just figure out the best way to navigate between them. New personalized services and applications have nearly infinite permutations of individual "screens", making the behaviour -- if/then rules, cause/effect loops, state-specific displays -- of the application more important than the traditional navigational elements. It becomes a question of managing variables rather than simply giving directions. Cooper has published articles about software behaviour in relation to marketing, but this takes it a step further into the realm of interaction design.
The shift to services may be driven by economics to a certain extent. Perhaps selling information online is unsustainable because it's too easy. As the difficulty and cost of web publishing has fallen to nearly zero, the availability of free alternatives to your very important content is almost guaranteed unless you have very timely and/or exclusive stuff that people just can't do without.
As Stephen and others have pointed out, services are different. I'm not going to pay for an article about how to find out who links to my blog because I know I'll find one somewhere for free. But if I'm curious enough, I just might pay Technorati a few bucks to get an RSS feed of new links to my site, because for me to create the software to do that would be impossible (or at least very difficult and expensive). Maybe the next financial opportunities online lie in helping people accomplish tasks with tools they won't be able to create on their own.