One wiki model
A one wiki model has been applied in some large public wikis that address very complex problems in politics and governance. Such a model has been proposed to unify the Consumerium Wikis presently proposed. Real life examples:
For instance the Green Party of Canada at greenparty.ca/lp implements its Living Platform wiki-based policy development and Living Agenda wiki-based governance projects with a single tikiwiki, using varying user permissions and user groups. This is an experiment and it's not clear it will work out.
The Wikipedia has used separate namespaces within one wiki to address most operational day to day problems, with such pages as w:Wikipedia:Votes_for_deletion and w:Wikipedia:Troll and w:Wikipedia:Vandalism_in_progress being part of the "Wikipedia:" namespace. However it retains separate meta wikis and others to address different issues, like Simple English Wikipedia to address simpler vocabulary needs for certain audiences.
The Anarchopedia eliminates sysop monopoly on the ability to undelete pages and so there are no controls on reading. This is the most open model most compatible with free software and open source mindsets. It remains to be seen if it can resolve various problems with language & power.