Rebecca's Pocket gives a good piece on the ethics involved in the world of weblogs. Why are blogs not taken more seriously out there by the mainstream media? Part of the reason is the trust factor. People trust The Washington Post and the New York Times because the reports in these publications have been proven factual over the years (minus a few glitches and omissions, of course.) The reason people in the blog world visit a few select big-name blogs is the trust we develop in these to be accurate and dependable. Visiting any random blog is like interviewing a person on the street - you have no idea what you are getting.
Much has been made of the 'checks and balances' that blogs have come to weigh in with on the media. Still, the notion of 'checks and balances' as they apply to blogs really only apply to those which have enough traffic to create a balanced system. 99.9% of blogs out there (according to figures established in my own mind) do not receive the traffic to truly make them a balanced vehicle of truth, though the lack of this accountability does not imply that they are not true. If I published on my blog tomorrow that Martians had landed in my back yard and were setting up a pizza parlor marketed toward Star Trek and Star Wars fanatics, the tabloids might show up to interview me but no one (or few) in the blog world would rush to my defense. Conversely, at a low traffic blog, the truest analysis is likely to get merely a passing yawn.
The interesting part about the whole system is the way that the big blogs are like a towering structure built with the smaller blogs as the support. Instapundit is 200,000 hits strong partially because of the information gathered from the blogosphere. Glenn Reynolds then both gives credibility to other blogs and is viewed as a good 'thermometer' for the accuracy of other things going on out there (taking nothing away from his own articles and original blog entries.)
On the flip side, just as a major newspaper can be burned by one of its own who decides to make up the facts for its stories, the blogosphere is infinitely more susceptible to such problems. Bloggers as a whole will never be taken too seriously just as letters to the editor in every small town newspaper across the country carry little weight until the proven name of the community weighs in with an opinion.