use case is manage content, prepare a new edition of a site all ready to synchronize with on line edition... another: have a drupal site on your desktop, synchronized with online, then, when you travel or can't get to a connection, you can still browse the data.
another: recently for the Argentine elections, the list of registered voters was distributed in a CD with an apache stack... here we could have something like a Drupal stack, although, as a Rich App instead of an apache stack. so, instead of distributing CD's with apache, etc., you can just have a rich app allow users to browse material offline, and even then sync with new content online.