The original goal of wiki usability was to see if there is the possibility to create some UI guidelines or specifications for wiki systems to improve their usability.
With participation of Twiki, TikiWiki and Dokuwiki developers, we realized:
1) the development of wikis is so divers that it is almost impossible to have a general UI for wikis. For instances, Dokuwiki is a simple wiki for small-scale usage, while tikiwiki is actually a wiki-based groupware integrated with blog, calendar and more features.
2) there exists a gap between user experience people and open source project developers, even the developers hope to find solutions for their usability problem, it is difficult to find resource. Maybe we lack UE persons in the open source projects.
We did a little face to face UI review for tikiwiki: Marc Laporte pointed out some tikiwiki's usability problems and I tried to give suggestions by experiences. Hope he found it helpful. The developer of Dokuwiki also welcomed the idea that maybe we can have face to face sessions for UI designers and wiki developers to improve the usability of wikis together. This may worth trying in the next wiki conferences.