Boing Boing is quoting a talk by Clay Shirky on what they're calling the "cognitive surplus", or the amount of human thought not taken up by necessary pursuits. (I think I'd call it "discretionary cognition", for a financial comparison). They calculate the human-thought-hours taken up by wikipedia, and find:

So how big is that surplus? So if you take Wikipedia as a kind of unit, all of Wikipedia, the whole project--every page, every edit, every talk page, every line of code, in every language that Wikipedia exists in--that represents something like the cumulation of 100 million hours of human thought. I worked this out with Martin Wattenberg at IBM; it's a back-of-the-envelope calculation, but it's the right order of magnitude, about 100 million hours of thought.

And television watching? Two hundred billion hours, in the U.S. alone, every year. Put another way, now that we have a unit, that's 2,000 Wikipedia projects a year spent watching television. Or put still another way, in the U.S., we spend 100 million hours every weekend, just watching the ads. This is a pretty big surplus.

As we consider and build the tools that put political information online, we should remember that we're tapping into something unimaginably vast; we get to help shape the answer of the question "what would all of those people be doing if they weren't watching television?".

Even if only a small amount of that leisure time gets connected to politics and government online, and it is well connected to the substance of oversight and legislation, of politics and elections, then democracy is going to go through a fundamental change. TV can't compete, and the sheer amount of human attention moving online and getting involved in participatory media has enough weight to shift both politics and government. Even if one in 20,000 cares about a specific GAO report, that's enough to make a drastic change, assuming people's interests and abilities are led to those places where their attention matters. To those places where their attention is important, where they can have some effect, where they can add to their knowledge, or to where their knowledge can be helpful.