To see some great research on the dynamics of building a community, check a series of posts by Christopher Allan:

http://www.lifewithalacrity.com/2008/09/group-threshold.html
http://www.lifewithalacrity.com/2008/11/personal-circle.html
http://www.lifewithalacrity.com/2009/03/power-laws.html

The numbers behind the approach are very interesting – helping to provide insight on what it will take to be successful on MIKE2.0 and the FISDEV projects. But my suspicion is that the dynamics for our approach are a bit different – due to the complexity of structured collaboration around a methodology (making things harder) and the greater sponsorship we have from corporates (hopefully increasing collaboration).

If you are interested in some great case studies on what it takes to get a collaborative community going, I highly recommend reading Christopher’s work!