Uh, publishers have been creating electronic textbooks for well over a decade. They simply haven't caught on for a variety of reasons.

Apple is simply a company with impeccable timing. They are fantastic at industrial design. Their marketing is brilliant, and radiates confidence while many competitors are timid. Yet they are never the first. The closest they came to a first was with the Macintosh, and even that was inspired by technology that was stuck in another corporation's R&D department.

As for the cost thing, I wouldn't expect there to be any benefits as far as the education system is concerned. Publishers and authors aren't going to adopt a new technology if it means that they will endure lower revenues and high expenses (multimedia texts are more expensive to create, due to both labor and licensing costs). Yes, there will be benefits: students will be able to keep textbooks and have to cart around less, but that is far from revolutionary.