Tom, this is what I hear David saying: It is evident that online participatory media make possible large-scale public input by thousands or more. Currently, no one knows an effective way to process and deliberate around this dazzling and disordered collective voice. Citizen Deliberative Councils don't seem like an effective way to process all that data, either. Online Robert's Rules of Order may be.
David, this is what I hear Tom saying: Randomly selected Citizen Deliberative Councils are an established and demonstrably effective process for gathering public input. CDCs are small-scale, low-tech, well-organized, and fairly representative of the citizen population CDCs don't have the same socioeconomic barriers to participation as online forums do. Online participatory media will prove extremely useful for generating representations of complex problems and discourses, quick-polling provisional outcomes of deliberation, or otherwise enabling large-scale support for face-to-face deliberation by a CDC.
My point of view: Both of you highlight that the technological tools have great potential but aren't there yet. Apparently there are some folks inside the Obama administration who've been given license to experiment (e.g. this site, change.gov, data.gov). No doubt these folks are scratching their heads as much as we are about how to organize all this participation. Assume the online tools of participation do develop, through experiment, as we hope. Practically speaking, at the end of the day, some group of people has to take whatever consensus/insight/diversity of opinion is produced by online participatory media and deliberate on what to do about it. This group of people will almost certainly be collaborating face-to-face, small-scale, low-tech. Currently, the locus of deliberation is only located within the government -- the particular group of people in the Obama administration paying attention. The goal is to invite more citizens to *that* party. CDCs seem like a reasonable proposal for systematically inviting representative samples of citizens into the deliberative process that does the hard work of turning insights generated online into concrete practice.