Just finished implementing a postgres backed powerdns system for internal dns including slony replication to a remote node which also has powerdns on it. I wrote some python which I hooked into the dhcpd commit, release and expire events that creates forward and reverse DNS entries for specific ranges of DHCP when leases are given and removes them when they expire or when they are released. The records are created with 60 second TTLs, so it seems to work pretty well. I got tired of editing bind files, now I can make DNS changes programatically or in a web GUI like poweradmin or something. There are also a bunch of new sub domains for lab, esx, vpn and proxmox hosts which are easier to manage now.