Besides WebmasterWorld, I am an active participator in a large online user-generated content project. The amount of user supplied content items runs in the tens of thousand items per day.
On such a large scale a small group of dedicated moderators is not a feasible solution anymore and instead the project has chosen for a hybrid system with a handful of dedicated moderators and the ability for all general members to moderate each other.
Aside from the problem of orphans of user-supplied content in some of the less crowded project areas, the system of user moderation works quite well. In this system users are assigned to different levels of posting and moderation rights, depending on the number and quality of their previous contributions. Level assignment is done on the admin level out of the sight of the members. So every member doesn't know how influential his/her contributions and moderation actions will be.
It could be an option for WebmasterWorld to reduce the number of dedicated moderators and instead make more use of the existing knowledge and judgment capabilities of the community to flag what is appropriate or not appropriate. Still general guidelines and some admins are needed to prevent that the system becomes a way to solve personal vendettas, but it might be an option to get the community more involved in guarding the quality of the threads and deciding what is appropriate and less appropriate content.