My response could be voluminous, but I'll keep it brief and just shed light on the idea. I have been a big proponent that Gov 2.0 and its fraternal twin, Open Government needed a happy medium between data and dialog to be successful. Unfortunately, data has received the most attention and the biggest challenge of the two, dialog, has lessened its importance in this discussion. Data is static. It's easier to tackle. Dialog is dynamic. And there is a history of challenges surrounding dialog that precedes the web.
So you stated it appropriately: "technologies." The main challenge will be government's ability and effectiveness to provide the required data for those third party facilitators of the public dialog that will return informed verdicts to the policy makers on how to vote on public issues.