I can envision a situation where the content is free but you can purchase premium versions with enhanced lesson plans and interactivity. Kind of like free and paid apps.
To make this a reality, I'd consider building a platform that serves as a centralized repository for open information/knowledge and gives the information some structure (Ontology). With that in place, people can build applications on top of the open information (interactive apps/charts, etc)
To encourage qualified people to contribute, edit, and update the repositories, consider layering in a Quora/StackOverflow type voting/reputation system with a Kickstarter crowd funding component to fund qualified folks and allow them to dedicate significant time to the project.
I could see this working well. I think these new types of textbooks would gain a foothold not by some epic battle between the entrenched publishers and open content revolutionaries, but simply by being affordable and valuable enough that students start using them in ADDITION to the textbooks they are currently forced to buy. Similar to Khan Academy's current position.
Then, if the ecosystem hits critical mass, it won't be too long before some professors and teachers start saying "wait... why are we making students use this crappy book again?"
I'm aware that the last part is a bit naive, but I think it's REALLY naive to think that we will see a massive legislature-driven transition to "the right thing" anytime before the sun goes dark.
To make this a reality, I'd consider building a platform that serves as a centralized repository for open information/knowledge and gives the information some structure (Ontology). With that in place, people can build applications on top of the open information (interactive apps/charts, etc)
To encourage qualified people to contribute, edit, and update the repositories, consider layering in a Quora/StackOverflow type voting/reputation system with a Kickstarter crowd funding component to fund qualified folks and allow them to dedicate significant time to the project.