The obvious quality control problem of maintaining a community-edited site like Wikipedia is getting some attention. Andrew Orlowski claims the well-respected online encyclopedia is hopelessly in need of rethinking and reworking. And Jim Horton laments the inevitability of uneven quality within a structure that refuses to establish hierarchical editors.
I've certainly seen some definitions that were flawed, but I still find Wikipedia easy to use and easy to link to.
It may not be perfect, but it's good enough for a lot of people.