wiki option means that the publisher of a feature
(editorial collective) or a newswire post (individual)
is able to "give the option" to others to edit the
post, as in wiki, instead of simply commenting it.
This means having and "edit" option available on the
feature/post - made available by the original poster -
so other users can contribute contents directely from
the web, instead of participating to traditional
editorial mailing lists.
Release 3.3 will have a feature that will allow selected stories to be edited by the public with an optional password. The idea is to use it for working documents and that these stories would be locked to comments. Depending on how this is used it may develop more towards wiki functionality
This could be partially implemented by adding something like [[pagename]] tags and Oscailt would automatically look up the redirect list to see if these map to any internal oscailt static pages. The editing part that you get with Wiki is less straight forward as that would require a login and is also a potentially security risk.