I am using Trello every day and I am finding it very useful. In my work deadlines are very important, looking at my trello you can find a lot of them. The problem is the way they are presented. You can only see them while looking at the particular task.
In my opinion adding feature like timeline would be very helpful. Project management-wise it would make app more useful.
Bartosz Stolarski about Trello: organize anything!, v3.4.4