A low impact (like git) way to colaborate.
I don't think that git supports collaboration as positively as a traditional wiki server does. What is missing, is something to encourage the eliding of abandoned repositories, and the coalessing of changes into a shared vocabulary of ideas.
dynamic queries are the key - as in Foswiki, giving authors the ability to embed a customisable query makes it possible to build anything.
defining schemas, using the wiki as a datastore, accessing non-wiki data as though it were in-wiki
how do i know that someone has forked (they don't have write access to my wiki), what changes they've made, and then do I pull their changes (and they can delete, or it converts to a mirror), push them and delete
I _think_ we need to contemplate different senarios - building a legacy document, building a personal view of a legacy document, scratching a personal itch,