I have a client who, many years ago, asked for a way to "mass edit" content items, e.g. change the value of one field to the same value that she could specify. We kind of hacked it via some Script (Python) and form controllers (yeah!) to let her specify the field she wanted to mass-change and then based on the field type a widget that let her specify the actual value... but that was then and this is now...
Is there a kind of "spreadsheet-like" way of displaying one or more (probably quite a bit more) content items (of the same type), and enabling inline editing on all those items' fields so she could paste a single value in repeatedly?
I'm also picturing a hack that uses a datagrid field that would be loaded with the values of all the specified items to be edited (one datagrid row per content item to be edited), then, on save, re-mapping the grid field values back to the actual content items and their values.
Users understand spreadsheet UI.