I can confirm that I'm having the exact same problem.
I'm also using Windows 8.1 Pro x64, R9 270X, 13.11 9.2 Beta drivers.
I receive a black screen during the driver installation process using both the Catalyst installer and installing the device driver manually through Windows Device Manager.
Powering off the machine and powering it back on again results in the Windows boot logo showing, but I'm never presented with a login screen. At which point, I'm being forced to reinstall Windows to get back to the desktop again.