JD Lasica has a great Q&A about blogs and journalism.
“Why a blog? Simple: to connect with other people. Sometimes I’ll have some advice or tidbit of information gleaned from folks I interviewed and I’ll want to pass that along. Other times I’ll have some questions that I’ll throw out to the Weblog community in the hope of being enlightened. But bottom line: This is where I’ll share my personal experiences and gut feelings about issues that matter to me.