I participated in the second annual Wikimania 2006 conference in Cambridge this weekend. Having set up and nurtured intranet wikis myself, I chose to go to a panel discussion on organizational uses of wiki technology. The panel was excellent. I particularly enjoyed the many tips the panelists shared on how to boost user adoption.
The tip that rang most true is "don't get in the way". This is probably the hardest lesson to learn if you like to tinker with wiki technology. What the panelists referred to is adding structure that hinders rather than helps user adoption.
Wiki is not top-down software. Its informality and openness are key to its effectiveness. The type of unnecessary structure you should restrain yourself from adding to a wiki is forms and automation that are compulsory for the user.
Everybody knows that there is more than one way to jot down meeting notes, maintain an FAQ, or compile a glossary on a wiki. While some of those ways are more elegant than others, it doesn't really matter how the information gets on the wiki as long as it gets there. Once there material is up it will benefit somebody.
So feel free to organize and categorize existing wiki pages. It helps information retrieval. But be wary of setting restrictions on how users should contribute new material. Forms and automation easily become just another barrier for adoption.