Is Glassfish an OS Project?
My opinion is that open source is two things-- open code and open processes. If the Glassfish project is ever going to form a community around their product, they need to open their processes. The code going in is available to everyone, but right now, their ideas aren't.
A project as big as Glassfish is like a moving train. Right now, with how talented the developers are at Sun, this train is moving very quickly. To someone who would like to get involved and contribute, they aren't going to easily be able to 'hop on' by peeling through the code as it's checked in.
What a potential developer would first need to do is get advance knowledge of the ideas that are being brought to the table. What's one developer thinking vs. another and where might your ideas help the project out? What's the next obvious step? Contributing your ideas in code.
I'm hoping that Glassfish will make that push to communicating on their Java.net lists. Maybe Sun's developers don't need any input right now, but input will never hurt you.