A friend has been having a problem installing Mavericks with the message: "The OS X couldn't be started my because the disk is damaged and can't be repaired".
We're looking into this error, but, judging from this Apple Support Communities topic, a lot of people are encountering this problem.
The friend was confronted with having to reinstall OS X and run the Disk Repair utility. Their advice is to run Disk Utility before you start the install in the first place as they now have to go through the whole process again.
Luckily they do have a Time Machine back up if everything goes wrong.
We'll let you know what happens.
Have you experienced this problem, let us know what you did to solve it in the comments below.