No wonder so many voted for it, it's really something needed.
I like the third option and registered editors is a good idea. I say go for whatever people are most comfortable with - open or closed access.
It will be a work in progress for a long time, so then the question becomes what makes up sufficient content, but whichever model is chosen at least has to be a bit polished first
I agree with Fnord except for the suggestion of using degreed experts as editors. That's not how most Wikis work, and it would be unfair to always ask for free original research/work.
There are many experts without degrees and there's a lot of information available under a creative commons license, like all (most?) of Wikipedia, like 1401b said...
I *believe* some of the concerns behind Fnord's suggestion would be resolved with effective administration.