Transmedia has become a real buzzword lately, but the problem with that term is that it puts the emphasis on the means - telling stories across various media platforms - rather than on the goal. The goal is immersiveness. Using different media becomes natural when you have a distribution platform - the Internet - that subsumes all media. But that's not the only way to reach the goal.
Frank Rose is the author of The Art of Immersion: How the Digital Generation Is Remaking Hollywood, Madison Avenue, and the Way We Tell Stories and a contributing editor to Wired.