No, but blogging has changed the rules of journalism. There are some blogs that apply journalist ethics to the blog medium and they become very powerful and popular. In the Philippines we have Raissa Robles whose blog is so well researched that she has a huge following simply because of her credibility. So this is an evolution of journalism and gives more power to people, has impact on a lot of important local issues and makes some senators in our country hate her. I think she has done a lot in terms of transforming the blog format into a more investigative type of journalism where she not only mentions her sources, she uploads the documents, videos, etc. In this way she also widens the former limitations of journalism. A news article had to just have the facts. Her stories include background, and all sorts of stuff.
But not all blogging is journalism. At any rate, why should it be? Blogging is an art all its own and I'm so grateful there are blogs I can read about dogs, about DIY stuff, interior design, et al and have full enjoyment. I love reading the thoughts of normal people and peeking into lives very different from my own.