In a Red Couch interview, Jonathan Schwartz put his finger on how blogs change the nature of interaction between journalists and the rest of us:

We asked him what blogging’s role will be in this new Era.

“It’s kerosene on the fire. The Participation Age has been on the Net since email. Moving from there to blogging is like moving from carrier pigeon to phone. The emergence of blogs means we have passed beyond early crude tools and it results in fundamental changes on how everything relates. While a journalist is writing about my blog, I’m blogging about his journalism. This is change,” he told us.

In a very real sense, blogs are the new "letters to the editor" - only the editor has no choice as to whether it gets printed. There's still no guarantee that you'll get more than trivial readership, but it's a far, far better chance than you had with the letter.