Ability to Hide parts of the code instead of deleting or removing it

When updating parts of the code such as custom fields it would be good to be able to select if you want to suppress items from being visible to users so that you don't lose existing data in the system.  This would be useful for pick lists.  If you are adding fields to a pick list and are removing others however you are not ready to have all the data migrated to the updated list you can suppress the old items from being visible to certain user types.  This would allow admins to push out updates faster while working to migrate details across their instance.