As a third-party user of MediaWiki, the removal of hit counters provides difficulty for myself and users. While not as accurate as other analytics packages, the count can be used to provide users with a list of 'popular pages'. This functionally is useful and should remain available in future MediaWiki releases, perhaps via an extension.
In my particular instance we use the count to provide a list of popular page on the Main_Page of our internal wiki. Removing this in 1.25 will render this list impossible to provide.
This also impacts the users of the following extensions. All of which have been relatively active in their development.