I've encountered a few connectivity issues with Windows 8.
If the USB device is disconnected while my app is open, Jazz does not receive notification of the disconnect. Replugging the device does nothing after this point.
If the app is opened before the USB device is connected, Jazz does not receive notification of the connection.
At the moment I'm using a popup warning to alert Windows 8 users of these issues. I'd love to hear if anyone else is having the same problems!