scored a picture of the upcoming AMD 770 based AX78 motherboard from Abit, and it appears that Abit has managed to make some kind of CrossFire workaround for this board, as it has two x16 PCI Express slots.
Officially, the AMD 770 doesn't support CrossFire, but it does support AM2+ processors and HyperTransport 3.0. The board has four DIMM slots for DDR2-800 memory, onboard Gigabit Ethernet and 7.1-channel audio with optical S/PDIF out and Abit's rear CMOS reset swtich.
There's also a single x1 PCI Express slot and three PCI slots, as Abit has left a gap below the first x16 slot to allow for dual slot graphics card coolers. The AMD 770 chipset appears to run quite cool, judging by the tiny heatsink, although it's connected to a heatpipe that transfers the heat to a massive heatsink on top of the PWM.
You can find some more info here
This is what the board looks like.