Found this article and decided to give it a go.
Wow, setting up a development environment with VirtualBox and Vagrant was quite easy. I had to fix up my Homebrew install because I haven’t gotten around to reinstalling Xcode after my new install of Mavericks. The command brew doctor was run many times to get it working 😉
I can now happily mod my theme(s) for work and test in a nice safe, sandboxed location.
Have a Happy New Year everyone.