A lot of number crunching is done on the Wikipedia content. Particular the most famous one, the English language version has a lot going for it. My favorite number crunching project is Wikiword, it tries to get semantic content out of Wikipedia. It is a great project.
Many statistics seem to proof what the researcher tries to prove. Aaron Swartz wrote a really nice article on who writes Wikipedia. It is great because it challenges conventional wisdom. The conventional wisdom is that a small group of people write Wikipedia. Aaron makes it plausible that it is the anonymous user who contributes the most letters to the article that you read in Wikipedia.
What is particularly important for me are the consequences for WiktionaryZ. The suggestion is that we have to make it easy for the casual user. That people contribute to the things they know and care about. That an intuitive screen helps, WYSIWYG helps people who are the writers, the wikisyntax is for editors, the people who make things pretty.
The user interface of WiktionaryZ needs to be compared against the user interface of Wiktionary. Wiktionary is flat file and almost every Wiktionary is essentially different. WiktionaryZ will have one user interface for all languages. Contributions made by some will be available to all. I trust that we have and edge.
The flipside of the coin is that indeed a limited group of people do the EDITING. What we do not have in place are tools that help editors. Editors are the people that will prevent WiktionaryZ from becoming a mess. Particular the merging and deletion of the [[DefinedMeaning]] and [[Expression]] will be important to get right..
There are ideas on how to do this, they are not mature yet.