I am currently working on getting a better grip on why DIX should matter at all, particularly with SAML around. Granted, DOX offers a few neat features, but I cannot see why SAML should not be able to support most of them either by profiling SAML 2 or adding a few details. My fear is that the DIX folks will re-invent SAML, only this time within the IETF.
I have created a page on my wiki (that contains only this blog entry so far) where I will collect some thoughts and ideas.