The main purpose of the blogs I read is not to supplant the [mainstream media], but to give expression to points of view which are being ignored by the MSM. I'll leave the reporting of facts to them (assuming they'll do it), but their monopoly over public opinion is clearly over. And as far as rumor-mongering goes, the 24-hour news networks have clearly shown no aversion to that. They'd rather be first than accurate.

Right, the overwhelming majority of blog posts (at least the ones that I read) are straight-forward commentary on the news and do not do any original reporting. The problem is that while the mainstream media does report, whole subjects seem to have been declared, officially or unofficially, off-limits for its consideration. Anything which doesn't adhere to an accepted mass consensual story-line is ignored or brushed off as speculation from the tin-hat crowd.

(The major media's bias originates not only blatantly, from the influence of conservative owners and high-profile reporters, but from this exclusion of "fringe" viewpoints which deserve more attention, since many of the allegations made have turned out to be true. Pandering, both to the audience and to the radical conservative establishment, plays a part as well.)

In another comment in the same thread, pragmatic_realist tells why having an independent source for commentary is important:

One of the main factors that allowed the Reformation to take hold was the invention of the printing press which allowed Martin Luther and others to disseminate their ideas and arguments outside the control of the church. Likewise the pamphlets and newspapers of Thomas Paine and others led to widespread support of the american revolution. Other reformers and critics led social movements in Britain by printing their own papers, and the government tried to break them by imposing taxes on printed material and fees on things sent through the mail. Remember the Stamp Act?

Whatever establishment is in control wants to supress information and discussion by controlling the means of dissemination and publishing. Now they argue that in order to be legtimate you need to be able to persuade people with money to print your ideas or put them on the air.

Of course cheap modes of publishing will put forth a lot of bad ideas, falsehoods and crank theories, but anyone with any sense has already figured out that you have to read everything with a critical eye and be prepared to work at verifying the truth and valididity of facts and conclusions.

More: David Neiwert has a good post about "balance" in the media:

Now, there is such a thing as real balance. Real balance is a genuine striving for truth: a willingness to both recognize and honestly explore the multiplicity of viewpoints as well as facts that are part of the naturally complex nature of truth. It is complicated and hard work. Of course, real, hard truth is elusive and rare; but the striving is what brings us closer to it.

However, a genuine balance does not countenance obvious falsehoods where it encounters them. It does not treat misinformation as a legitimate "counter" to reasonably established facts, as though a falsehood were just another opinion. It does not put lies on an even footing with facts.

Unfortunately, that is exactly what we have gotten, in increasing doses, as standard practice from the nation's press for the past decade.

Also, Atrios reminds us of the overwhelming absurdity of some of the claims made, by people the mainstream media took seriously, during the Clinton-era failed right-wing putsch -- I mean, crack pipes on the White House Christmas tree??!!.

What unbiased, objective, reality-based journalist would give the person making that charge even one second of extremely expensive and hard to come by media time?

Update: Blogging may be mostly commentary, but it's not all commentary. This piece about Gannon/Guckert is an excellent example of blogging as open source journalism.