From the wording of your original post I would wonder whether what we are really talking about is a new PDF version in which appropriate details are embedded to allow ereaders (with Adobe supplied software
) to read PDFs as if they were in an ereader relevant format. That is: one file format PDF, but able to be read as a traditional page layout on large screens (as PDF was originally intended), but also as a flexible format for small screens (as ereaders need). I could certainly see that as appealing, and feasible.