ATI is preparing a new GPU, the RV570. This chip will replace the current Radeon X1600 series. The ATI RV570 will likely feature 256 bit memory and the CrossFire bridge chip embedded in the core.
This will let the manufactures to make bridgeless and connector-less Crossfire systems. You won't need a master card and all the dull cables any more. It will also cut the production cost and will finally make the Crossfire upgrade path easier. Time will erase the necessity for the master and slave design. Even next generation R600 comes with a Crossfire bridge inside of the chip
Two cards based on RV570 chip will work together and, if you want to make a dual chip RV570 card, you won't need a bridge chip on the PCB. It will simply work and it is the way to let the manufactures make Quad Crossfire systems as well.