"Last week, blogger and public relations executive Steve Rubel conducted a news experiment: He gave up his regular media habits (newspaper, online, radio, and to a lesser extent TV) and learned what was going on in the world solely by checking weblogs."
He found that he could not keep up with the news as well, but this makes sense since alot of blog posts assume some level of news exposure. If something big happened on TV I might talk about it, but I would not recount the entire event since I would assume most people are aware of it. (Or would click through the link)