So here are two problems I have with tags, one is a problem now, and one will be one later. Regardless, I like the fun that has been happening around tags, but I wanted to do a brain dump about this:
People who tag their posts are not always qualified to do so. For instance, if I were to tag this post as being about tags, I'd say that's true. If I were to say this post was about technorati, it'd be only partly true. If I said this post was about internet architecture, then it would be only generally true. If I said this post was about my thinkpad, it'd be pretty much untrue. This is a bad example post, but suppose I was writing a post about coding opengl using the swig bindings to python. So I could tag it as swig, python, java, graphics, gaming and opengl. Well as you see there are a number of words that mean many things. Java could mean coffee. Graphics might mean design. Gaming might mean board gaming or poker or cards and python.....you get the point.
People will use tags to spam. Remember how people used to use meta tags to add contextual information to web pages? I remember when I was running svlug, someone suggested adding porn to the meta tags to draw more traffic. Needless to say, I didn't do it, and I avoiding having to talk with that person at meetings as he was clearly broken, but anyhow....that's enough about that.
So have fun tagging, but don't get too attached to it :-)