By any chance if you re-run the configuration management wizard in Sharepoint 2013 Preview, you are rest assured that you will have to re-install SharePoint. When it's run for the second time it deletes the SharePoint Config Database and there is no option to recover it unless its backed up before running the wizard.
Microsoft has confirmed it as a bug. Let's hope its resolved in RTM
And I am one of the victim of this issue :(