In our team we use TCAL to visualize anything from our project, from sprints & release schedule to team leaves, etc. In particular, we display the upcoming sprints with the sprint "goal" for everyone to see.

Since we cannot currently see JIRA Agile's "future sprints" in a calendar, we created a custom event type called "future sprint". The problem is, contrary to the built-in sprint event type, our future sprints events are not line-up. Instead, they will stack randomly with other events. During periods where lot's of team members take vacations, the future sprint events will be all over the place. This is far from ideal. We're not asking for swimlanes, but simply a best effort to regroup events by type.