I agree that it would be nice to more clearly see what the parent task is. Right now, when I'm in a subtask, I can see the parent task name at the top in small gray letters, but having it more evident would help sometimes.

On the other side of that coin, I wouldn't want the interface to end up too cluttered.

Let me start with a common example from my own life: I am looking at the tasks on my list deciding what to do next. One of the things on the list is "Call Lynn." But why am I calling Lynn? If I click on the task, the right-hand pane open for that subtask and that subtask only. I clearly see that we are trying to negotiate a lower rate with our power company. Lynn has scheduled a meeting with one of their reps. I put a subtask on RTM to remind me on the appropriate day to call Lynn to discuss the results of the meeting. Here's my suggestion...As part of the name of the substask, include (in light gray italics perhaps) the first little bit of the name of the parent task). That way, as I scan my task list, I am automatically seeing the specific small things (subtasks) and ALSO a clue to the parent tasks all in one glance.