Casio Japan have today announced the release of the second generation of Bluetooth enabled G-Shocks which follow the release of the G-Shock GB-6900 bluetooth earlier this year. The new release consists of the GB-5600AA model which is based on the classic square DW-5600 along with the GB-6900AA which is identical to the previously released bluetooth GB-6900. The G-Shock GB-5600AA is available in four colorways and the G-Shock GB-6900AA available in five colorways. It's unclear from the release what differences ...