The number of articles so far is pretty limited, but they are working hard and it looks like they are doing things the right way. They seem to have an honest spirit of inquiry and cooperation and are building an original and well researched body of knowledge. This is a worthwhile project, and it would be worthwhile for anybody who has something to add to contribute.
In general, I’ve found Samurai Archives and their related forums to be an excellent resource with far less ego and argument than most of the martial-arts focused forums I follow.
I think it is a notable that the martial arts community has a poor relationship with wikis. The relevant articles on Wikipedia are prone to errors and pointless edit wars. Independent wikis have failed to take-off much, although there is a Sword Arts Wiki and the Martial Talk Encyclopedia, neither of which are very interesting so far. I think that part of the problem is that those who are truly knowledgeable are not interested in writing/marinating information for “outsiders,” leaving fanboys and zealous acolytes to write what is out there (see this thread). The other problem is that martial artists are notoriously bad at working together. Of course, who am I to complain when I am writing for my own site rather than contributing?