Blogging lowers the barrier to web publishing and has a reputation for being more authentic. It all depends on what you mean by authentic. To my way of thinking, the compelling benefit comes from pushbutton publishing, and it's the possibility of interaction.
I read an interesting post by Steve Rubel who was attending the Blog Business Summit over the past couple of days. He was reporting on a presentation about using blogs for emergency PR (his profession). Reading the post, I wondered what it really had to do with blogs. It seemed to me that he was really just talking about a web communications channel, of which blogging is one example. So, what's so special about blogging?