Some articles from around the net that talk about SCA/SDO and Tuscany. Candidates for the Resources section of the Overview page on the web site.
osoa.org - Current home of the SCA/SDO Specs
(OASIS Open Conposite Service Architecture where the specs will be)
osoa.org - Interesting SCA resources
osoa.org - Interesting SDO resources
Real SOA - Web services and Service Oriented Architecture
What is SCA
What is SDO
Holy grail of services: SCA
Taking your first steps with SCA
What can Service Data Objects do for your SOA system
Implementing Platform Independent Data With SDO
Henning Blohm - Setting Out for SCA
David Chappel's Introducing SCA
http://www.infoq.com/news/2007/07/scaproblem#view_8587
Feathercast Issue 35 (http://feathercast.org/) talks about Apache Tuscany