Grouping (see below) to see how complete at different levels
Tasks and Sub-Tasks (Expand should be easy :p)
Assignments - To an actual person or a Type, you dont know whos free yet but you know youll need 1 of type x, 2 of type y. Can then auto assign free people or be prompted with who is available and choose them.
Dependencies
Copy/Clone/Template function to repeat projects/tasks etc