Modules|Themes can be tagged by the owner of the module. And will improve search results:
Example: Module "Views" Tags:(Display, Content, version Dev, Beta, etc...) and filtered by it's version v6, v7 etc.
Theme: Tags(Colors, Columns, Dev, Beta, HTML5 etc...)
http://drupal-association itself is using this feature but it is not found on drupal.org.
Tags are also used on blogger.com blogs for better search results.
I think you all understand well what I'm talking about so vote. :)