When I plan the roadmap, I know the expected date, and the team velocity. I can then guess a total backlog size I can expect to do in that timeframe.

I'd like to be able to select items (SHIFT+CLICK or CTRL+CLICK) in the JIRA Agile Planning Board, and see the total amount of story points for that selection. That makes me able to do several things;

1. If I need to remove N points from a release, I can select items until I reach that number, and then drag them in a new release
2. If an item is cancelled and I free up N points for a release, I can pick and choose items until I reach that number, and drag them in the current release