I see what you meant--having two for redundancy--but I was much more excited by the idea of having two where both had to be valid, as getting two organizations

I see what you meant--having two for redundancy--but I was much more excited by the idea of having two where both had to be valid, as getting two organizations to issue you a bogus certificate is going to be a hell of a lot harder than getting one (not impossible, but often an entirely different kind of attack). Maybe we require three and at least two have to be valid, providing the benefits of both angles? ;P