So you're talking about a curriculum for a programming class? If so, read on.
Most of the teachers I work with would prefer to use the curriculum provided by their district because that's what their colleagues are using. This isn't out of laziness, but because it's helpful to have someone else teaching the same stuff so you can bounce ideas off each other. Rather than selling to educators, you might actually have to sell to districts. But computer science is such a small part of most districts, buying a curriculum for two or three teachers is likely a low priority.
I'm not sure if you're targeting Middle Schools (which to me seems like a very small market. I can't think of a district near me that offers programming to Middle School students) or High Schools, but many High Schools only offer AP programming. This must be taught in Java and due to time constraints it must be taught to the test. That makes designing a curriculum very difficult and most teachers would be hesitant to look at game design.
That isn't to say there aren't markets for stuff like this. I was in the market for it three years ago. Plus what we do offer at Middle Schools (Word/Excel/Web Searching) could be dramatically improved.
I did put together an ebook for my class, but I deliberately stopped short of offering it as a pdf/epub. If I officially listed an ebook as my text, I'd potentially be in trouble with my district for not making the text accessible to students without a Kindle/Nook/Computer.