It has been in process for a little while, starting when I moved the bulk of my DNS hosting from http://www.bytemark.co.uk/ (with whom I’ve had a small virtual machine since April 2004). One of the things I really like about Bytemark was the free DNS hosting they provided, particularly since they used TinyDNS - which is worthy of its own post. To add a new domain name, create a small file with the relevant lines, with one per DNS record - really easy if you have any kind of database or automation.
Back in April (2012), I came across a post on HackerNews to http://www.luadns.com/. This is a system that again, uses TinyDNS as a backend, but instead of some hacked-together PHP scripts I wrote to produce the data files, they are run through a Lua script. That gives the benefit of very easy to read configurations, and then the files themselves are stored in a Git repository, which can arrange to notify the main luadns website whenever it is changed, so the records are updated whenever the repository is.
So, with the use of the service from luadns, I had a good reason to a) move my DNS off bytemark (with the intention to also eventually shut down my old server there), and b) tidy it up as I went. So I did. I had already moved my tech-blog to http://phpscaling.com/ last year, and over this last few weeks, I added http://abulman.co.uk/ to the same Wordpress installation.
Supporting different domain names for (at least) two different blogs isn’t too easy in a stack Wordpress 3 installation. It isn’t made any easier becuase I also have a couple of domain name aliases that point to the http://abulman.co.uk/ site (there is also http://alisterb.co.uk/, and of course there is also the www.* versions) and so I was having a lot of trouble till I found the wordpress-mu-domain-mapping plugin. While it’s not quite a drop-in plugin (you have to copy some files around manually) and of course setup the IP address and domain names, it solved my problem.