deltalounge

At the end of the SOA Symposium 2009 the SOA Manifesto was ready and declared. It is based on these principles.

SOA Manifesto

Service orientation is a paradigm that frames what you do. Service-oriented
architecture (SOA) is a type of architecture that results from applying service
orientation. We have been applying service orientation to help organizations
consistently deliver sustainable business value, with increased agility and
cost effectiveness, in line with changing business needs.
Through our work we have come to prioritize:

Business value over technical strategy
Strategic goals over project-specific benefits
Intrinsic interoperability over custom integration
Shared services over specific-purpose implementations
Flexibility over optimization
Evolutionary refinement over pursuit of initial perfection

That is, while we value the items on the right, we value the items on the left more.

source
You can watch the Announcement of the SOA Manifesto on Youtube.

The manifesto was signed and declared by: Ali Arsanjani, Grady Booch, Toufic Boubez, Paul C. Brown, David Chappell, John deVadoss, Thomas Erl, Nicolai Josuttis, Dirk Krafzig, Mark Little, Brian Loesgen, Anne Thomas Manes, Joe McKendrick, Steve Ross-Talbot, Stefan Tilkov, Clemens Utschig-Utschig, Herbjörn Wilhelmsen. Soon you can join them in signing the manifesto on soa-manifesto.org.

Update Oct. 26th
I found some blogposts of people participating in the creation of the SOA Manifesto: Clemens Utschig and Stefan Tilkov