Add an "active watchers" count to MediaWiki's info action.
Not quite sure how we'd do this, but it seems potentially useful. On older wikis, the number of page watchers stat can quickly become meaningless without further context (i.e., a number in a vacuum doesn't mean much). If we limited the count to "active" users (defined by having made an edit or action in the past 30 days, I suppose), it might be more helpful.
From a suggestion here: https://en.wikipedia.org/w/index.php?title=User_talk:MZMcBride&oldid=559641049#Number_of_watchers.
Description of functionality now available in 1.26: https://www.mediawiki.org/wiki/MediaWiki_1.26#Information_of_actual_watchers_of_a_page