I agree that having a wider range of question types would be a huge boost to the Lesson module. If you followed the developments of the Moodle Users' Association last year, you might have noticed that making the entire suite of question types available to the Lesson Module was one of their proposed projects. (Actually it was the project that received the most votes in member balloting). Unfortunately, the cost and complexity of project led the Association to choose a different undertaking (a revamped Dashboard, I believe). I still think there's a lot of hunger for this among Moodle users, so it's good to continue discussing it in the forums...