Upstream report: https://secure.phabricator.com/T5024 (possibility to query all tasks in a column -- which would allow to close all of them with batch edit)
It would be neat if there were a way to close all tasks/cards in a particular workboard column. As an example, take a look at the Team Practices Group's workboard (screenshot attached) - there are 11 cards in the 'Done' column. It's annoying to have to go through one task at a time to update the status to 'Resolved' and would be much nicer if I could select an option from the list along the lines of 'mark all cards resolved'.
Trello provide a feature similar to what I am describing - there's a dropdown menu at the top of each list on a Trello board with a bunch of options, one of which is 'archive all cards on this list'.