Context : CommandLine
I think there might be a fundamental mismatch between wiki and what some people call EaseOfUse
One of the strengths of current wiki, in my opinion, is that it's "the return of the command line." Wiki format is just about one of the only "language" based UIs, based on the computer parsing simple instruction strings.
The idea of the GUI, WYSIWYG and direct manipulation by mouse of every little detail is so ubiquitous that there's an assumption that everything must evolve towards that. But in fact, the GUI is designed to help naive users. Experienced users often prefer the command line, or keyboard short cuts. I believe most would prefer to go further. To have more linguistic control of their software once they've mastered it.
But most systems these days are not designed with linguistic operation in mind. If you have to manipulate the same stuff in the same order every day, you'd welcome being able to reduce that to a single line command (or even batch script) You'd take the effort to learn.
The fact that most software doesn't allow this is a break on the productivity of using new software.
Update : Interesting comments on the above : http://boston.conman.org/2007/05/29.2
AzaRaskin talks to Google about it : http://video.google.com/videoplay?docid=-6856727143023456694
Interesting to think about the confluence of this way of thinking (no applications but composable functions - BangTheRocksTogether) with FunctionalProgramming, the DeviceSwarm and its reasons (SystemsEvolvingTowardsSmallerMoreSpecializedComponents) - perhaps we can imagine an operating system written rather like a SwarmOfServers (perhaps ErLang programs) - or maybe it's the "compositionality" of the parts that's important ... does that mean they need to be more like Monads?
In fact, a SwarmOfServers operating system could almost be like a SpreadSheet in that any server could just suck data from any other, leaving the OS kernel to calculate the order. At the top level would be UI widgets pulling everything ... in fact it's a PullPlatform :-)
Teaching the command line : http://osnews.com/story.php?news_id=6282
Mouse considered harmful : http://www.stronglytyped.com/archives/2004/06/09/mouse-considered-harmful/
The dangers of GUI-ism http://getpot.sourceforge.net/GUI-ism.txt
See also :