The XMEGA's UARTC0 is connected to a software UART on the AT90USB1287. The AT90USB1287 UART is communicating at 9600 baud, using one start bit, eight data bits, one stop bit and no parity.
When the AT90USB1287 device is enumerated (connected to a PC) the data transmitted from the XMEGA is passed on to a (virtual) COM port. This means that it is possible to use a terminal program to receive the transmitted data on a PC. Similarly data transmitted from the PC COM port is passed on to the XMEGA UART through the gateway.
If the USB device is not enumerated, e.g. powering the kit from an USB supply adapter, the AT90USB1287 device's UART will operate in loop back mode (echo back everything it receives).