Two proposals for CIDR-style IN-ADDR.ARPA delegation were presented at the
DNSIND WG meeting of San Jose's IETF. Both were thrown out, one due to its
complexity and the other because it had bad failure characteristics (and I
mean Really Bad) during a network partition.
If you can show me that we can avoid the complexity than I will be a happy
man. The complex solution works (at least in small, test envrionments 
And I agree with Vadim on the point that WHOIS is flawed.