You see a lot of people doing open source, but not a lot of people doing open development...At some open-source projects [Erenkrantz mentioned Mozilla], all of the technical decisions, even if the license is open source, are not subject to public comment. At Apache, everything is done in the open over public forums.
This is the exact philosophy we follow on the Mach-II project, and I feel it's one of the secrets of our continued success. Letting our community know what we have planned and getting feedback before writing any code helps us meet the needs of our users better by giving them exactly what they need, not what we think they need. Springing features on users is no way to do a truly open source project. Involve your community at all levels and it pays off big time.