As Paul duly noted in his blog entry Working in the Cathedral
the model for PostGIS development is morphing, but I wouldn't call this morphing process one that is entirely toward the Cathedral model. Unlike the perceived Cathedral model, I would like to think we will have more frequent releases and beta releases, perhaps parallel experimental builds and most importantly, more fun.
The main idea being making it much easier for mere mortals and fake mortals to taste test the cookies in the oven while they are cooking. By fake I mean unit tests, build bots, and computer generated people where the fear of destruction is removed.
I feel this is the similar model PostgreSQL goes by or is trying to achieve.