Editing multiple cases in one case-structure to make them execute nearly the same piece of code is a pain at the moment. Combining the functionality of "Add case for every value" and "Copy case" would be such an helpful feature to have all cases look nicely and speed up changing the relevant parts of code in the case-structure.
Why would one need such a feature? Imagine some kind of generic API that manages multiple incoherent hardware interfaces in one place. Depending on which hardware interfaces are needed (dynamically) there's an array handed over to the API that contains the interfaces to start (asyncron). Let's say the API decides via a case-structure which interfaces are "named" to be started, then the only thing to change in every case is the "static vi-reference", but at the moment you could either copy one existing case x times for every startable hardware interface and have to change the case-name and the "static vi-reference" or you could add cases for all values but have to fill every case's funtionality anew.