The truth is, no matter how much new technology comes running into our lives and no matter how many mountaintops the tech evangelists find to shout from, politics -- the kind of old-fashioned, gotta-get-more-votes-than-the-other-guy politics -- really does not change.
Voters depend fundamentally on two things to make their decisions. First, they want to know the candidate is a human being they can relate to and would even invite home to dinner with their family. Think about Ronald Reagan and Bill Clinton versus Bob Dole and John Kerry. Second, voters look for cures from those people they know and trust. This might be their minister, their local labor president, their spouse, their co-workers, or even (Heaven help us) a celebrity like Oprah Winfrey or Charlton Heston.
The dot-commers in the late 90s traveled to DC insisting that EVERYTHING was going to change and that those Luddite senators, congressmen, and especially the back-room-cigar-chomping-money-grubbing POLITICAL CONSULTANTS would know that the train hit them only when they looked back and saw the caboose on its way down the track. Ooops. Didn't happen. Al Gore and George Bush and John Kerry still had massive campaigns going door-to-door with clipboards, held campaign rallies and rubber chicken fundraising dinners, and good old-fashioned call-me-at-dinner phonebanks never stopped running.
Disintermediation / Giving more voices more outlets
On the other hand, this YouTube thing and technology in general has truly democratized the power of communication and information in politics. Howard Dean's presidential campaign manager Joe Trippi talks about "disintermediation", which may in fact be the truly revolutionary thing about technology. If you assume that information is power and you want to accumulate power (what good DC politico does not?), then getting and hording information is your pathway. The Internet has disrupted this whole thing. Access to elected officials is easier because of telephones (once a new technology itself), the Internet, well-read political blogs, citizen journalists researching and spreading data, and the occasional Macaca who chases a Virginia U.S. Senator around until he says something just plain stupid and ignorant helping cost the poor fellow his seat.
Journalists vs. people
There are differences and advantages in having regular folks ask questions rather than journalists. This is true for a regular, in-person town hall as well. For example, one journalist on CNN actually admitted that there are questions that he would never ask a presidential candidate, though he knows that regular folks might ask them. (When pressed to offer an example, the reporter declined! What are they afraid of?)
Finally and perhaps most importantly, the CNN-YouTube debate provides something that is essential to a thriving democracy -- a way to participate and a belief that citizens will be heard. Whether citizens have this opportunity because of a novel use of new technology or because they simply feel like the system is responding, the CNN-YouTube debate is great for the process.