The recent discussions about the deployment of features for supporting vetted/approved pages and trusted authors, starting with German Wikipedia and perhaps expanding to the English one, is interesting in light of one of the few analyses of whether it is best to review a contribution upfront, or after the fact. (This is like the arguments in programming about whether it is better to write code in which you "look before you leap" or just leap with the knowledge that "it's easier to ask forgiveness than permission"). If you haven't read it, and you are short of time, just have a look at the discussion and conclusion which includes:

These results suggest that Wiki-Like systems create value faster than Pre-Review ones. Most people contributed under the Pre-Review system overall, but since people prefer editing to checking, a backlog of wasted work builds up. The model also suggests that Pre-Review group will do about the same as the Wiki-Like group in the long-term However, contributions taper off faster than predicted Pre-Review systems may increase people's willingness to contribute... or deter people from damaging the system... compared to Wiki-Like. (Cosley et al. 2006:9)

Also, one provocative observation is one could start with Wiki-Like then switch to Pre-Review as contributions taper off; "However, imagine the outcry from its members if Wikipedians were to switch to a Pre-Review system." (Cosley et al. 2006:9)