I am working on Commons:Template:Assessments which reports "featured" status files on commons. There is a synchronization problem with local wikis and commons.
For instance if a file is a Featured Picture on English Wikipedia, Assessments template would have the parameter |enwiki=1 and optionally |enwiki-nom= to link to the nomination page. If a file is a formerly featured picture the parameter would be |enwiki=2. If the file is a featured sound the parameter would be |enwiki=3 and if the file is a formerly featured sound the parameter would be |enwiki=4. Updating the commons page is sufficient to update all wikis since the starts are visible on all wikis.
Though it is also possible to run the code in an interwiki.py-like manner as well as featured pictures are typically not interwiki linked.