Nice thoughts!
When I think about wiki, I think about team work.
After read yours comments I could find (googling) a proprietary solution called Confluence[1]. Maybe it's what I'm looking for. Lets see...
Maybe we could define it as "collaborative editing of information".
Wikis is one technology, maybe tagging (and voting) is other technology, multiuser editors, mmm in the late days we can see "inline comments" too...
The way wikis solves that, is adding certain ingredients as "revision history".
There is a tool nowadays by excellence, for "revision history", and it's named "git". In the late days people speaks a lot about "github for writers" and things like.
Google apps, and alternatives, offer a step further (i.e. you can use google-sites as wikis with permissions, but integrating rich widgets).
mmm
We could say that stackoverflow and etc are a wiki based on questions/responses/comments...
I could prefer a CLI wiki (that you can edit with vim, render from markdown to ASCII colors, and query with ack or grep). But I don't know if this paradigm could be considered a "shift". Maybe it already exists, just that I haven't used it.
First thing you should consider in whatever platform/solution you're thinking is:
a) Attribution. Do you prefer to enable anonymous contributions, or do you prefer gpg signed ones?
b) Content access. Are you thinking about public wikis, private wikis ? This may change totally the solution...
Maybe a paradigm shift may emerge if you look at new devices... smartphones, etc... is a "mediawiki" a nice solution to "collaborative editing" on a smartphone ? doe it take advantage of the device capabilities?
The most beloved bash script collection S2