The SamuraiWiki is ever evolving, and for the forseeable future it is set to only allow "approved editors" to edit and add content. This will make it easier to keep tabs on the academic veracity, and will prevent random people from signing up just to vandalize, or for people to simply copy and paste information from other websites or wikipedia.
I haven't developed an "application process" yet, however it won't be terribly difficult for interested and motivated people to become editors. Current "regulars" at the Samurai Archives forum and the Samurai History yahoo group are all immediately eligible, and until I create a yahoo group for "new" editors to apply, contact me with your interests, and I'll consider making you an editor.
The SamuraiWiki is simply an alternative to Wikipedia with a focus purely on Japanese history. It isn't "in competition" with wikipedia, however the lax standards in scholarship and citing sources on Wikipedia reduce its value in anything other than a casual informational resource. The purpose of the SamuraiWiki is to allow people to get information that is verifiable and useful for academic study and further research, and as such, the focus is currently on both primary sources and Japanese language history books and academic research.
The Webmasters of the Samurai Archives don't consider it "our" website, we are hosting it as an archive for Japanese history on the internet. This being said, it is not an "open history" source, nor is it considered "public license" - all posts to the SamuraiWiki become copyrighted property of the website, and will not be used for profit or for posting to any other sources without proper citation. As of this post, there are currently 1155 articles available. The current focus is on the Edo period, with particular attention being given to the Shinsengumi, however there are aways additions being made to other categories and topics. Hopefuly this will become a respected and useful resource for people interested in Japanese history.