This OpenID proposal ignores existing XML-based standards that provide the very same functionality.
These alternatives are admittedly somewhat obscure in the industry, little known specs like SOAP, WS-Addressing, WS-Security, XML Signature, and XML Encryption.
Fortunately there appears to be no duplication between this proposal and WML. Consequently, at least for mobile markup we don't have to worry about convergence. Bullet dodged here for sure.