Ray Jimenez is the Chief Learning Architect for Vignettes Learning.  I have watched a webinar he presented on Training Magazine network, and he does a good job sharing his thoughts on story-based eLearning design.

Our belief: At Vignettes Learning we use stories in eLearning; however, we make them interactive. The emphasis is getting learners involved in the story and not just telling the learners the story.
Synthesis. Story-based eLearning design is effective because it creates an environment where learners are compelled to anticipate. The vagueness of “what’s next” keeps the mind engrossed until the story finds a resolution. Very few people can resist the power of a good story.