The Bizhub C250 Printer by Konica Minolta has no official Windows 8 drivers yet, apparently some updated Windows 8 drivers will be released in July 2013 if all goes to plan. However I can confirm that the Windows 7 drivers appear to work perfectly on Windows 8.
I tested the Bizhub C250 on a Windows 8 64bit install using the Windows 7 64bit drivers. Our setup consists of a networked Bizhub C250 with a static IP address. The Bizhub C250 driver installer found the printer on the network, installed the drivers and set its self as the default printer.
After that everything worked the same as it does on our Windows 7 machines, including the various overlays we had created.
Hopefully this post will be of use to people wondering if the Bizhub C250 will work on Windows 8.
Update: Official drivers for the Bizhub C250 dated the 08/07/2013 are now on the Konica Minolta website.