On the Really Strategies blog I have posted the first in an occasional series of examples of how to apply the DITA 1.2 keyref feature to specific real-world problems. The entry is here: http://blog.reallysi.com/2009/04/dita-keyref-example-links-from-glossary-entries.html
Over on the Really Strategies blog I've posted about the fact that DITA, while it has lots of cool features that get a lot of us very excited, DITA can also be applied to the simplest applications. Because DITA, by dint of its unique features as a standard XML architecture, has the lowest possible cost of both initial implementation and long-term ownership, this makes DITA a compelling business choice simply because it saves money and time relative to almost any other alternative you might choose.
The Financial Accounting Standards Board (FASB) has gone live with it's new Accounting Standards Codification (ASC) Web site, a DITA-based application that provides all of the U.S. Generally Accepted Accounting Procedures (GAAP) standards through dynamic delivery of DITA-based content.
I have written up a deeper discussion of the project here: http://blog.reallysi.com/2008/01/live-dita-appli.html
The ASC site itself is here: http://asc.fasb.org/home
I have posted some thoughts on using DITA for narrative documents on the Really Strategies blog: http://blog.reallysi.com/2008/01/dita-applicatio.html
The executive summary is:
By ignoring the existence of the <section> element you quickly realize that nested topics can be used just fine to represent narrative documents with arbitrarily deep nesting of divisions. This potentially opens up a whole class of documents of particular interest to Publishers that might otherwise not seem to be good candidates for ditification.