This idea was originally submitted to MVLC as ticket #184, based on phone conversations and I believe Tom has done some work in this direction.
The general idea is to make it easier for staff to manage items that temporarily in different locations - like items on display, in the new book room, etc. There are different use cases based on the context, so different interfaces or approaches might be ideal.
One case is items on display. Currently, the way to mark display items is through copy locations. However, when a "non-fiction" item is changed to "display" the original copy location is lost. Also, the display item must be manually changed back to its original copy location. It would be helpful if there was an option that allowed the copy location to be automatically reset to the "permanent" copy location when the item is checked in - this will avoid items being reshelved in the regular place but still marked as "Display" in the catalog (which invariably happens).
Another case is new items. Ideally this could be a time-based temporary copy location, that would stay "new" for either a number a months or a until fixed date (set by the library) before reverting to the permanent copy location. However, since the copy location change has to coincide with physically moving the item (and probably removing stickers from the item), it would be nice if, after the set amount of time, checking in the item would trigger a prompt for staff to reprocess the physical item and confirm the copy location change. Another useful feature would be use the check-in screen just for the activity of "un-newing" items. If a whole batch of books were to be removed from the new books room at the same time, they could be pulled from the shelves, have the stickers removed, and then checked in to force the copy location change from the temporary "New" to the permanent copy location.
There may be additional use cases for temporary copy locations. As I said above, I believe Tom has talked to a few MVLC libraries to see how this could benefit workflow.