At the MVP summit, I learned about Grava. This new educational product from Microsoft is both an authoring and developer tool. Here's an example of what I mean:

If you've been in the education market for long you can see that this application looks like an application created with Hyperstudio. What's different about Grava is that the product has its own SDK built on Windows Presentation Foundation (WPF) and provides a programming model and tools for building rich educational experiences.
I learned how to use Grava and developed an application on the History of Gaming that I can use with my students. It was pretty easy to put together in a weekend and I'll show it to my students soon to see if they like it.
I'm sure book publishers would like this product so developers can create applications to compliment the textbook used by students.
Check it out if you want.