Here's the very talented Pablo Defendini — developer, designer, artist, digital guy — describing how "responsive" comics can be made using HTML and CSS that intelligently format themselves for a variety of devices, and addressing the writing and illustration challenges this gives rise to. He's not talking about "motion comics" — he's talking about comics where the layouts and writing take into account a range of screen-sizes and aspect ratios.
Responsive design works for websites, why not for digital comic books?