I’ve just started reading the ePub3 Overview and my head is spinning. A lot of it has to do with rendering other languages, but some of it could be specific to poetry. I’m basically interested in the CSS portion, but ePub 3 only supports CSS 2.1 and some CSS 3. So this is of interest mostly to publishers looking for ePub translations as text. Still, if you have an interest in eBooks and the ePub standard, it is so worth looking over.