X.509 certs that don't guarantee identity

On the 23rd, Jeff Weinstein said this concerning the natural semi-anonymity of the net:

Given that verisign and others will soon begin issuing large numbers of certificates that do not guarantee the identity of the key holder, it seems that this tradition will continue even with the wide deployment of X509 certs.

This has been bugging me since I read it. I'm not sure I understand the plan; it only makes sense to me if "anonymous" X.509 certs are issued for user authentication only, not for server authentication. Is that what this is about? (If anonymous certs are issued for servers, why should such a cert be treated any differently than one I generate on my own, which causes warning screens about an unknown CA to pop up?)