What's new in DITA 1.1:

Version 1.1 of DITA provides enhanced print publishing capabilities with new DITA Bookmap specialization, including extended book metadata. The standard offers more indexing capabilities with new elements for "see" and "see-also" references. It features new elements for defining structured metadata as well as the ability to add new metadata attributes through specialization.

The specification files (HTML and PDF Spec documents, DITA source, DTDs and Schemas) are available here:

http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=dita#technical

The Overview is a great entry point into the various parts of the DITA 1.1 standard:

http://docs.oasis-open.org/dita/v1.1/OS/overview/overview.html