It's a four year old machine. I'm assuming that Apple will announce some awesome new kit at next week's press conference and my wife will get her boss to buy her one of these new things. Assuming we're looking at multiple weeks for delivery, that's how long I need to keep the old machine running. After that, it's job becomes "random backup / utility machine". I wanted to spend as little money as possible on this project.

Meanwhile, I'm now trying to install OS X directly on the hard drive to make it bootable (instructions). We'll see if this works any better.