Here's one of those articles in the Telegraph today which sets out to reassure their readers that it's now safe to mention your blog at cocktail parties, the kind that kicks off with a broad apology for the medium's early adopters, before consigning them to the history bin.
Personally however, I think the blog style is at its most interesting when it approaches soliloquy − sometimes it's actually worth trying to express yourself as if you have an audience of one. I have to check myself occasionally when I discover that my own blog is becoming too declamatory and uni-directional, too focused on an imaginary virtual auditorium around it.
Without at least a degree of introversion a blog simply becomes old fashioned communication flowing from a different format.
I don't think of blogging as a cheap form of therapy, but it's a very useful way of assimilating new information through quite formalised reflection. It's rather like opening up your own private input-output port and keeping a regular log of what passes through it. Organisations that adopt the form but forget to look within as they speak without might be both missing the point and asking for trouble.