The Special:Tags page, which is what was previously the category page, has a title which is not useful at all. e.g. the build glossary at http://developer.mozilla.org/Special:Tags?tag=Build_Glossary&language=en has a title of "Site Tags" I know that there was talk of customizing the tag page to provide an editable section or something, but in the mean-time I would at least like the page title to be "Pages tagged with Build_Glossary" or something similar.
Filed with MindTouch: http://bugs.developer.mindtouch.com/view.php?id=4929
Has been fixed for a while. Now the page title for tag lists is 'Pages tagged with "Build_Glossary"'.