This isn’t really something that I am too into at the moment but there has been quite a bit of interest in this type of feature for Movable Type and TypePad, more so the former. It turns out Six Apart are either listening or are moving in the same direction as their users (most likely both) because Anil Dash posted on the Six Apart Professional Network that these features will soon be coming to a Movable Type or TypePad blog near you. I may be a little off on the TypePad side as the post does mention "TypePad affiliate programs". Anyway, take a look. Here is the post:
Hot on the heels of the release of Technorati Tags comes a Movable Type plugin
which will automatically generate keywords for a post to populate the
Keywords field in Movable Type and then create links to Technorati tags
for those keywords. Slick.