I use PowerDNS too, but with BIND flat files as a backend. Setting up replication is even easier than MySQL: I just rsync the flat files from a central server to my 2 DNS servers whenever I make changes. PowerDNS automatically reloads the files based on their mtime.
Yeah, I'd considered that, and there are some serious advantages to flat files. To be honest, relying on MySQL for production anything makes me nervous. But: SQL queries occasionally save my butt when needing to make lots of changes all at once, instead of having to figure out sed again or edit lots of files; and, I wanted something that would sync automatically, since I'm an idiot and sometimes forget to do something like an rsync command after a change.
