Reading a post by Allen Searls (Doc's son, I assume) about the idea that the Desktop (i.e. your main screen after logging in or booting up your machine) is slowly being replaced or supplanted by the browser is not a new one (no criticism, just a thought). I was praying like mad this would happen back when PointCast (the link does not lead to the original, push news and content company I remember from 1996) brought out their push content client in 1995/6 (I can't remember exactly when it was but I do remember playing with it when working at Hillsdale College). I was excited because the PointCast service could be integrated with Microsoft's (then) new ActiveDesktop concept. The Desktop was not a static image, but a multimedia, ever changing landscape of information, etc.
The problem related to an active or ever changing Desktop is practical(ity), however. I think many people treat the Desktop on their computers just like they treat their wooden/glass/steel Desktop in their offices or homes (or school, etc). While interesting at first, it eventually becomes a distraction that we want to remove (or we go crazy not realizing what it is that is forcing ADD upon us). Think about it this way: what if your Desktop was replaced by your plasma or LCD display? Do you really want a constantly changing stream of content in a place where most of us would like some amount of consistency and calm? If so many of us did want the constant bombardment of new information (news, email, etc), then why would a program like WriteRoom be popular (perhaps it's not a shooting star product, but it has gotten its share of good reviews and commentary along the lines of, wow, that is a great idea!).
The main problem, however, is reliability. What killed PointCast for me (besides the company's apparent lack of ability when it came to creating bug free software) was the fact that when it failed, it failed miserably. Most of the time, failure involved locking up my machine and forcing a reboot. Other times, it failed in gathering content even though my connection to the net was wide open. I think of how often I travel. I depend on consistency with the machines I take with me. Because the internet is not ubiquitous - especially for anyone trying to watch what they spend - it becomes even more problematic because if I come to rely on a system, and in this case, it is a system of information delivery, what happens when the plug or "wire" to that system is pulled and I can't access the content? I lose the functionality that I've come to rely upon. This is a function of availability and reliability - e.g. can I rely on getting the content I want wherever?
I must agree that the browser is becoming a more and more powerful tool in how we create and communicate. It is a major part of the Desktop as we use it today. I would argue, though, that the same was true in 1993, when I first signed up for Prodigy. The browser was always getting more powerful and it always will, but standalone programs still seem to have the best chance at over-all success because of their stability - hence, their reliability.