The Inquirer heard the upcoming DirectX10 compatible R600 GPU from ATI won't need a master card or a cable to work in CrossFire.
ATI will implement this bridge in its upcoming RV570 and RV560 chips and will enable more than one chip on a PCB configuration. But it won't be until R600 that this cable-less Crossfire comes into action.
R580+ will be the slight redesign of the existing R580, so don’t expect miracles here. You will still need a master card and a cable to plug them together.