The Publishers Weekly article "S&S, Disney Try New Models" describes Simon & Schuster's new "vooks", a multimedia approach to publishing that combines literature with video on either your computer or mobile device. It's described as a good venue for "content that will never make it into traditional print".
I'm challenged to believe a publisher would ever say "no" to the possibility of subsidiary rights. If the vook fails, they'll want to salvage whatever they can by repurposing this content; and if it succeeds, they'll want to expand that success to additional markets. Expect to see vooks make the leap (backward?) to dead tree editions eventually.