By semantic, I mean that information in the source document is marked up by type rather than by position/appearance. See for example the new tags in HTML 5 (the next iteration of HTML).
http://en.wikipedia.org/wiki/HTML_5
Note that semanticity does not preclude fixed size layouts. My point is simply that the more important aspect of information distribution is making the distribution more semantic, rather than better laid out. The advantages to making the information moe semantic far outweigh the advantages to making it better laid out. Given that, a format that is designed primarily to facilitate layout is unlikely to be the future of digital information.