When I first converted my old blog to Wordpress I used tags for all the old categories. This was probably the wrong choice as tags present more subtle meta-data about a post. After manually updating a whole bunch of posts I discovered Wordpress already has useful "Tags->Categories" and "Categories->Tags" tools to help with the clean-up. So now my tag-cloud is a little less dominated by the generic "general" and reflects the distribution of posts a little better. It remains to be seen if this is a good thing.