At the recent OWASP Switzerland chapter meeting, I have presented OSA. We have got some positive and constructive feedback and look forward to more contributors :-). Most importantly we have heard again that also for security architecture pattern applies: "the more the merrier"
You can find the presentation here:
OSA Presentation 2009 April (http://www.opensecurityarchitecture.org/cms/images/OSA_Docs/OSA_Intro_Presentation_April_2009.pdf)