Thinking some more about the trust thing I've decided that the whole scheme using 'open source contributions' as the basis for certification is completely orthogonal to the problem of keeping the signal boosted on a message board.
After all someone with a Masters in English (and I have someone in mind who fits this example perfectly) might be able to comment quite well on technology issues, or even open source itself. They would, should the certifications be accurate, be unable to post though.
OTOH, I, which would most fairly be called a 'Master' in this system by virtue of the amount of time I spend on cetus-links.org and other open source projects (easily 40 hours a week both paid on non), am not always to most interesting guy to listen to rant on a given topic.