Many years ago, designers at Xerox, Apple, Microsoft, and IBM each contributed to what became the user interface standard for personal computers. Back then, issues like whether individual windows should overlap were hotly debated. Of course, all of that is now behind us and the basic elements of the user interface of personal computers are amazingly consistent. Sure there are some differences between OSX, Windows, and Linux systems but there are vastly more similarities than differences. Enhancements to these systems are also not dramatic. Such should be the case so that users can have a mental model of how these systems work and that mental model shouldn't change very often. Of course, there are some basic problems with each of these systems that nobody is willing to fix at this point because the standard is so ubiquitous. A number of details could have been changed quite dramatically in those very early days because users hadn't yet built up a mental model.
We're witnessing another major wave of this type of phenomenon right now. The introduction of the Apple iPhone and iPod Touch 2.0 represent the beginnings of a new user interface standard for multi-touch mobile devices, and likely, multi-touch devices of all sorts in the future. It is therefore wise for all designers to explore and experience this new user interface for themselves. I've spent significant time with the new user interface and am of the view, consistent with many others, that the design is exemplary. It should be pointed out that the design is appropriate for the device it was designed for - the iPhone/Touch. I'm less sure that the design will be appropriate for other non-mobile devices that it may well be used for in the future. And remember that Apple has had difficulty in the past with successfully adapting and evolving designs such as was the case with the iPod when it started to include content in addition to music. If the experience with personal computer user interfaces is any indication, flaws in the designs of this new mobile user interface standard may have already been introduced and we have to live with them for a couple of decades.