A lot of talk about usability nowadays. Foundation even managed to pick up a sizable grant to try and improve our projects in this regard. I've been arguing that we need better editing tools for a while now, even going so far as to create some of my own tools to try and make things easier for new editors.
I'm a technically inclined person, so I personally don't find wikis too difficult to use. Of course, this is in comparison to some of the other work I've done in the past with HTML and LaTeX markup for documents. I also do a lot of coding work, so symbols and markup and parameters aren't anything new to me. But I'm one of a relatively rare breed of technically saavy people. The vast majorty of people in this world aren't as comfortable with plain-text editors and markup as I am. Hell, the vast majority of people in my family, and at my work, and from my school aren't comfortable with those things either. It's just not the kind of computing that people have been trained to expect.
Wikis are hard. They're hard for the radical conceptual reasons of openness and freedom and collaboration. But they're also hard for the technical reasons: strange and cluttered interface, and the ad hoc markup language. On top of the challenges inherent in MediaWiki, there are the challenges of writing a book, a whole book. It's a lot to deal with, and even if we write all sorts of documentation, it won't be enough. Books are big, they're structured, and they need a particular flow and cohesiveness to them that don't just happen when you click Save page.
Some people won't be able to find the documentation. Some people just wouldn't read it anyway. Nobody is going to read all of it. I haven't even read all of it, and I've personally written a good portion!
We need some form of WYSIWYG, even if it's very simple. There are too many people that just can't or just won't use Wikitext. We need automation, at least at Wikibooks. Books consist of multiple pages, collection pages, table of contents, introductions, and appendices. They have templates too, and categories. We need a button to "Create a book" given a few basic parameters that will create all these kinds of pages automatically and correctly. We need the software to take care of the technical and repetitive work, and leave the authors to do the basic book writing. We need the software to follow the rules, so the contributors don't have to read volumes of documentation just to learn them. If the software just does things the right way, the barrier to entry will be so much lower then it is now. Until we have that, the only people who will be writing books are the technically-saavy editors, a very small subset of the people who we would like to have writing books.