Felipe Ortega wrote:
Wikipedia just entered a new phase. Our responsibility (as long-time Wikipedia researchers) is to find out the causes (not necessarily negative, please read a PDF summarizing a recent electronic interview for the Strategy plan, at http://strategy.wikimedia.org/wiki/Interviews) and prevent any possible problems as much in advance as possible.
Why not also conduct interviews with Wikipedia editors, either a random sample or targeted people (for example, people who had significant contribution and then stopped).