A request for comments about the specifications of the new media file request dumps is ongoing. They will provide the basis for file-level usage stats, so feedback from the GLAM community that has provided Wikimedia Commons with hundreds of thousands of images and other media files so far would be very welcome.
Images on Wikidata
Magnus Manske wrote a blog post about how many images are being used on some of the larger Wikimedia projects. His analysis suggests that Wikipedia articles (across languages) could benefit from more systematic inclusion of relevant images already known to Wikidata, and he has a tool that works in the opposite direction - adding images to Wikidata based on the corresponding Wikipedia articles.