This new extension will create a new database table for article quality and importance (in the default configuration), and/or whatever other attributes the wiki owner may wish to configure. This will allow RecentChanges and other listings to be filtered by these criteria. It will be possible to set and modify the values of these fields by API or by tabs/dropdowns at the top of the page. The wiki owner can configure the fields to allow any value (presumably implemented by inputbox), or only those values that exist in a list (implemented by dropdown menu.)
For rationale, please see http://en.wikipedia.org/wiki/Wikipedia:VPT#Create_article_quality_and_importance_fields_in_the_database .