Compare this with a more traditional method of maintaining an open source project. Alan mentions SourceForce as an example. It’s not the only one. You have a central repository where a few people act as committers who can control what changes can go into its repo. GitHub on the other hand provides a new perspective. See the graph for Ruby on Rails for example. With a decentralized view like that you can quickly find out who meddles with the code and who are the people having a keen interest to contribute.

Amount of politics that’s going to be generated around the project is very limited compared with a centralized cvs/svn repo project. You can get rid of all those private mailing lists and just carry on with what matters most, after all code speaks on everyone’s behalf