When planning a Scrum sprint, I use the concept of extra tasks. Extra tasks are not part of the sprint goals, but are the next priority. If all tasks in the sprint is finished early, the team carries on with the extra tasks until the next sprint planning meeting.
I've just started using TFS with the Scrum template for a new project and not found a good way to handle the extra tasks. Ideally I would like to have them semi-included in the sprint. They should show up on the sprint backlog, but not be accounted for on the burndown graph.
What is the best way to handle the extra tasks with TFS?