many of the concepts and functionality that enable blogging have been around in one form or another for a long time.
What may be new, though perhaps not revolutionary, in the context of "knowledge power" is the ease with which blogs allow ordinary human beings (hopefully with real knowledge and experience) to publish their thinking to a broad audience. You don't need to be an HTML expert or a Webmaster or a content management guru or a geek of any kind to get your ideas out there in, literally, minutes. This is what good technology should be like - invisible to the user.
The added benefit of RSS is that if you want to benefit from the fresh content of a particular blogger without going to his/her site several times a day, your RSS feed will bring you the updates. You can also use RSS as a kind of always-on search engine which looks for new dynamically-served stuff inside all the RSS-equipped blogs on the Web, and serves it to you when available. Ordinary search engines are really poor at finding dynamic content, really slow to acknowledge it, and quite hopeless at making it readily available.