I'm a big fan of creating task lists, however, I don't think anyone's going to solve this problem by making the user do the work, no matter how nice the design.

There was once an Australian company called Liaise, which went a long way toward automating the task creation process by automatically identifying action requests within email. To me, this is what I imagine the future of this activity will look like. Here's an old Liaise demo video, which may help illustrate the point: http://www.youtube.com/watch?v=UyrWD7hTnFc