Wikipedia is not a knowledge base. Wikipedia _is_ an encyclopedia.
Jimbo has said that Wikipedia is a free encyclopedia and that it must be free and that it must be an encyclopedia. I think he means it, too.
Most of us--a consensus, in fact--are committed to that idea.
I'd like to emphatically second this. Wikipedia is and will always be an encyclopedia. It may extend the concepts of traditional encyclopedias, for instance I doubt Britannica will ever include an article on every incorporated place in the United States, but Wikipedia is still an encyclopedia. It is not a general base of knowledge. If you want something other than an encyclopedia you need to do one (or both) of two things.
1) Get some support for your idea. Talk about it on meta. Get more support for your idea there. Talk about it on foundation-l. Get more support for your idea there. Then, ask for the creation of a separate project.
2) Just do it on your own. Start wikinerds or mcfly or wikinfo or wikitravel or wikiteer or whatever other project you want to start.
In the case of a general base of all human knowledge, you're probably better off with method #2. I don't think there is a whole lot of support among Mediawikians to do this, because I think most Mediawikians see it as overambitious. I might even agree with them.
Anthony