I'm wondering how this will work with categories / namespaces? Has any thought been put into that?
If I build a 4E psychic conversion, do I have to 'fight' for the Psychic Warrior link with house rules for 3E? Do we turn all of the common names into hub pages? What if someone else wants to take the class in a different direction? Do we end up with /PsychicWarrior4E~Destil and /PsychicWarrior4E~PirateCat
I love the idea of a wiki for fan content (though I'm not crazy about discussion pages and I think just linking those back to the forum is preferable), but we're going to need some community standards before I really put a lot of effort into getting stuff there...
We''ll figure it out! That's why we have useful people like you in the community who know what the word "namespace" means!

... and speaking of getting stuff there, I have two Media Wikis for various house rules/d20 offshoots I've messed around with. Is the import feature functional?
It is, indeed: http://www.enworld.org/wiki/index.php/Special:Import
Although I'm not sure what pemrissions are set for it; it seems to work for me.