<< I didn't look back through all the topics here so I apologize if this is redundant >>
Something to consider, is a standards document. I've been looking through some open source PHP projects the past couple of months and I'm impressed with how some of them organize their projects. One thing I like is that a few of them had a "STANDARDS" document which defined coding standards for the project.
I know that each of us has our own way of coding and doing things, but for a project of this size and used by so many people, I think it would be a good thing to get people to follow some standard.
This was discussed in a topic in the internationalization forum a while back. And I agree, at liest for the base code, there should be some sort of set standard.