In German we have two contradiction proverbs: "Gleich und Gleich gesellt sich gern" ("birds of a feather flock together" *) and "Gegensätze ziehen sich an" ("opposites attract" *).
When applied to couples, I think both are true but for different aspects: for social status, education, religion etc, coming form similar background makes things easy. But when it comes to character, being of different kind is good because my partner might have something I don't have and together we are more "complete".
Diversity in open source is similar. There are areas where diversity is absolutely vital and other areas where diversity has a very negative impact.
Bjorn criticized the "lack of diversity" in the eclipse community because most projects are "mono-vendor". He is right, we need more diversity here!
But there is another kind of diversity that is bad: if there are many ways of doing the same thing. Excellent system are not designed by committee, but by a few people (often a single person) with strong ideas about architecture, design and the "right way of doing things" (Frederick Brooks calls this "Conceptual Integrity"). This leads to excellent systems. From my experience I learned that it does not matter much, which set of rules are applied, as long as the rules are consistent and everybody in the team believes in them and follows them.
Startup companies often get this kind of consistency "for free", because they grow form a small set of people and they hire only new people that fit into the "mind set" of the team. Open source projects, created by some enthusiasts, get it, because they attract people who believe in the system. The (original) eclipse platform is an example of such a consistent system.
I am afraid that the future of eclipse is in danger if this wrong type of diversity (I call it chaos) increases. (I wish the architecture council could help to defeat this kind of diversity, but I am afraid that the council is already way too diverse when it comes to "architecture")
It would help a lot if there would be a set of developers paid by the foundation coming form different backgrounds but with a common mind set when it comes to technology. If the foundation would hire people, I am sure we could find a great team of people that would be able make eclipse ready for the future.
Having a "vendor neutral" team of developers dedicated to the future of eclipse would give eclipse a boost. Else, I am afraid, eclipse is "auf dem absteigenden Ast" ("heading south" *)