User blog comment:Sarah Manley/New Editor Scheduled for Sitewide Release/@comment-93604-20110907161829/@comment-26686429-20110907162006

What do you mean by "delete categories" - if you mean remove them from the page, you do exactly that, edit the page and remove the link to the category. If you want to delete a category page itself, then you just delete the page (make sure everything's removed from that category, too - the links now show up as blue by default)