Fascinating blog-forum over at How Software is Built on deep dive analysis and community conversations about software development models - closed source or open source? Read it, then go read The Starfish and the Spider: The Unstoppable Power of Leaderless Organizations.
I can't wait for the reality TV Show: "Two teams of software developers. One open-source, one...not-so-open. They have 30 days to ship the same solution. Which one will survive and win?"