In several forums I have argued that the contribution of blogs and the interwebs to our knowledge of the "truth" in news is one-sided: We don't so much learn about definitive truth as we get decisive and embarrassing corrections of bullshit masquerading as news reporting. The idea that there is "truth" is shaky; the idea that there is demonstrably false crap is where bloggers come in.
A fine example of this genre is KPC pal M.G.'s piece on shale oil. I'm pretty sure this would embarrass the Times reporter, if the Times reporter were capable of embarrassment (meaning, he couldn't be a Times reporter, I guess). The Times keeps firing its "public editor," who is supposed to be their conscience. I don't think the current public editor is long for this world, if he is going to commit actual journalism like this.