What Tim O'Reilly saw many moons ago is now becoming clear even to me. The web is going to take over; the browser will be our window to the world.
In that line, let me revise what I said about tabbing and browsers in a previous post here. What is actually happening is that the tabs are becoming the windows, as the browser increasingly is going to become the window manager. As Bloglines is taking over from desktop news aggregators, other web-based applications (take GroupOffice as an example) will take over from other desktop applications. Web services such as Flickr will take over from local photo management suites. What I said about the browser turning into the operating system was spot on: this will happen. From the perspective of the browser alone, the change is seamless. If you take other applications into account, the migration may be a bit bumpy. I would predict that any desktop environment that smoothly integrated access to web services such as Flickr, Blogs and data storage on Yahoo or simple ftp hosting services, with local applications for file manipulation, such as office and image manipulation software, will do extremely well, even financially.
Curiously, this is what .Mac should have done - I can only guess that its platform dependence made it unattractive, a disadvantage that has been Apple's deliberate bane for a long time.
And hence my post about version control for the desktop, with the link to an article about keeping all your settings in version control on the web.