USV's Brad Burnham has a good post about web services and open source software today. One of his paragraphs could be taken out of context and applied to a lot of other things, especially community groups.
If the architecture is designed to further the interests of the community, it will thrive, if it is designed to further the interests of the community sponsor it will not.
If you look around at "tech community" groups in New York, you'll find some some with architecture clearly designed to "further the interests of the community" (nextNY and the NY Tech Meetup are two of them!), and some clearly designed to further the interests of their sponsor or organizer (I'm too political to call them out here so use the comment section if you'd like).
The point is that interest is not something you can sanitize or put make-up over: it exists in the "architecture" or DNA of the group.
I use nextNY as an example because it's about as community oriented as it can be. When people ask "Who runs nextNY," most people can only say, "Well, Charlie kinda founded it..." but then the conversation turns to all the cool things that have spawned out of it because our website is a wiki and anyone can plan anything they want and the only formalities are that someone, in the end, has to hold the passwords to the blog and wiki and Google Group.
NY Tech Meetup is more formal, with Scott and Dawn listed as "Organizers," but if you've ever seen a group get "Gonged" off stage (happened last time) or hung around to "mix" after the presentations (of nearly only NY companies), you know that the community really does power things -- Scott, Dawn and the team just set up the shop, and no one really questions their motives. And we thank them.
In closing, I should note that Brad follows the quote I put above with two more insightful paragraphs:
Those of you who know me know that I am a passionate advocate of open systems. But the cacophony of claims of openness is now obscuring the more important point. It is time to get over the idea that the goal is an open architecture. It is not. (...)
So let's stop debating whether a service is open or not and lets focus on the defining that perfect balance of freedom and structure that will result in vibrant, innovative communities.
Brad is right here. The objective, whether building a community around a web service or around a sector and a city, is to build innovation. Meetups and discussion board stimulate the mind and form new synapses in our community's collective intelligence. The openness facilitates a level of serendipity, but other factors, some proprietary, are hugely important, like Leadership, which goes beyond "organization."
If you're a "community organizer" and you radiate self interest, perhaps its time to take note and start leading: it's a balance between promoting openness while taking charge.