For 0 A.D., Erik Johansson steps down from project leadership and Michael D. Hafer assumes that role.
In Unknown Horizons, Nightraven steps back and Kilian fills the project management role.
Leadership in free and open source game projects is an exciting topic with much opinion about which style will lead to a successful game – whatever the subject’s definition of “success” is – and too few examples to make objective statements about it.
Are you following any specific projects and their leadership structures an want to comment on these? I must admit that I am out of the loop with many, many projects, although I am pretty sure that for example Flare, NAEV and Valyria Tear have (successful) Benevolent Dictator for Life style leadership.
On related note: FIFE (the isometric 2d engine used by Unknown Horizons) moved to GitHub.