Here is a survey to help shape a future OWASP certification. The questions you will be most interested in (aka security focus areas) come towards the end. So make you way through the first page. I skipped a few questions I didn't really like (i.e. don't give up if you find a few you don't like).
By the way, I think this is a great idea if done correctly. I think OWASP is in a good position to offer a nice certification for app security.
Found out about this survey from this post Enterprise Architecture: From Incite comes Insight...: Certification of Software Development Professionals