After ages and ages, the XHTML2 Working Group of the W3C has published an updated to their core document - XHTML Modularization. This update is currently a Proposed Edited Recommendation. Assuming all goes well, it will become a formal recommendation in about a month. You can see more about it, review the changes, and comment on it via http://www.w3.org/TR/xhtml-modularization.
This publication: Linked Data Patterns has some interesting ideas and hints about how to present structured data. It dovetails nicely with my current work on RDFa and general interest in ensuring that computers can readily derive meaning from content.