[DiapDealer]

The people who want to take advantage of new-fangled, multi-media-whoozy-whatsit-books will already own a device/app capable of handling them. The people who think new-fangled, multi-media-whoozy-whatsit-books are the devil won't be buying them. They'll be buying text-only novels from their favorite authors. Which will be readable on their existing devices/software whether they're in the EPUB2 or EPUB3 format. Unless you're worried that your favorite authors will be held at gunpoint and forced to publish whoozy-whatsits, there's no real reason to panic.