The April 2008 issue of STC's Intercom magazine is packed with interesting articles about DITA. The contents can be found here:
http://www.stc.org/intercom/index.04.2008.asp
Whilst some of the articles are acccessible only by members, the STC have kindly made an article about DITA & Wikis freely available:
http://www.stc.org/intercom/PDFs/2008/200804_18-21.pdf
Cover story available
I have made my cover story on DITA Tools from A to Z available on DITA News.
http://www.ditanews.com/tools/STC_Intercom.pdf
Please consider joining DITA Users to help support such research articles.
http://www.ditausers.org/membership/why_join/
Bob Doyle