In this release of Outlook, we considered adding subtasks, but decided that the primary problem that our customers are facing is that they dont use tasks at all. Some might argue that this is because tasks in Outlook lack the hierarchy and sophisticated linking that some time management philosophies call for, but what we found in our research was quite the opposite: tasks were already too complicated, they were hidden away in an infrequently visited section of the product, they didnt interact well with the calendar, and generally, they were too hard to use. We also found that less than 2% of our customers ever used tasks. We found this statistic to be incredibly sad given how badly people need better time management tools. To help our customers, we decided to focus on making tasks more prominent (the To-Do Bar), improve task interaction with the calendar (the Daily Task List) and most importantly, make tasks easy to create (easy task entry in the To-Do Bar and new task flagging.) Simplicity won out over additional hierarchy and complexity. Perhaps next release we will consider enhancing tasks to include subtasks and better hierarchical structuring to build on the system that we have built in this release. Thank you all for your comments.