Although I am not a fan of ATI (bad personal experience with them), I found this item interesting.
A new ATI advisory is out, and it looks like ATI fans are in for an interesting surprise; X1300 and X1600 won't need a master card. We confirmed this with a few AIBs over the last few hours, but it appears that ATI will release a new driver soon that enables Crossfire over the PCIe bus on Radeon X1300 and X1600 video cards - eliminating the need for dedicated master cards.
...These bridge-less, cable-less Radeons will represent the purest vision of a multi-GPU configuration. Rather than purchase a BBA (Built By ATI) master card, any AIB or BBA Radeon X1600 will work together in Crossfire mode. AIB partners could not confirm as to whether separate graphic card families would also work together in Crossfire mode.
Hopefully Crossfire will give SLI a run for its money. After all, competition fuels innovation, and innovation brings forth new stuff... and new stuff makes today's best cheaper!