About Kathy Sierra's blog death threats, it highlights one of my problems with blogs and my overall lack of surprise about the matter.
Blogs, in and of themselves have fewer homeostatic mechanisms than forums or listservs. They are primarily a voluntary push medium with the ability to respond. I have never felt like I have been part of a conversation as part of a blog; only as a journalist or lecturer. They have never made me feel "part" of anything, they have only made me feel part of an audience, and it is this belonging that is special to networked conversation.