For once, I feel that I am in complete agreement with Marc. Consensus doesn't cut it when you have a thousand participants in the discussion rather than a hundred, unless you want to resort to voting - which is effectively a tyranny of the majority.
Is a single leader making the final decisions really better than a "tyranny of the majority"? If the right person is chosen as leader, then it could work, but it's very difficult to find such a person.
One option I've been considering recently is some kind of parliament with elected members of the community discussing and making policy decisions. I don't think we've got to the stage where anything like that is needed yet, but if the community continues to grow it will eventually become impossible to involve everyone in every policy decision.