There are changes to the DNS that are practical and those that are not. For
better or worse, I can't see any way that teaching DNS to use new classes
makes any sense at this point. The only point at which it would have made
sense was when internationalization happened. But the path chosen makes
ICANN will manage whatever bits of the DNS consensus agrees it should
manage. The only events likely to break consensus would be an attempt by
some government to strong arm ICANN into a breach of faith with the
community and succeeding or some really spectacular peculation.
It seems to me that if people want to do anything new with DNS that they
should use prefixes, new RRs or both as the mechanism, not the class which
is limited anyway.
DNS is not a full service directory. Nor does it need to be. A UDP packet
is big enough for a link, a fingerprint and a digital signature. That is
all that you ever need.
The X.500 and UDDI models were broken because there is no point in putting
information into a directory if the service can return it in a service