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 more sense.
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 handshake.