Jeff Rice writes about the reported dangers of blogging in Inside Higher Ed: the fear that something one writes will offend someone somewhere, and thus damage one's employability.
(It's probably too late for me.)
But Rice encourages us all to take things a little less seriously, pointing to a long history of vigorous and intelligent, yet playful, experimental, and even eccentric writing.
There's nothing really unique about blogging from a writer's perspective, other than its current faddishness. The same things were being said about posting to newsgroups and publishing websites. And the same can be said of casual conversation, if/when overheard by others and taken out of context.