hm, that's interesting. i recently read an article about html vs. xml called "
unwebbable" talking about why "not every “document” can be a “web page.”" it specifically mentioned scripts / screenplays as classic examples of documents which have specific formatting requirements which don't translate well to html (characters, dialogue, stage directions, and also approximate time represented by one page of a screenplay), although xml would be able to handle them. i would have thought some of the same layout problems (if not the syntactic markup ones) would apply to a (non-pdf) ebook format, although i suppose in some situations they wouldn't matter as much.