Just like Asus and Abit Crossfire motherboards, it will use the ULI south bridge that comes with more features in the south bridge. Some boards such as DFI use the SB450 south bridge and this is part of the ATI reference design. DFI went early with the board and wanted to use ATI's north bridge and south bridge.
The MSI RD480 Neo 2 board uses the RD480 north bridge and ULI 1573 south bridge and of course supports 939 CPUs only. I wonder is anyone going for socket 754 version of Crossfire, but so far we haven't heard about such a design. The board supports PCIe 16X, in Crossfire mode it works as two by 8X PCIe express. It has one PCIe 1X slot, one PCI slot and some special Orange MSI communication slot. The board supports four SATA 1.0 ports, quite strange for a new motherboard, 7.1 HD audio, Gigabit LAN and it uses MSI CoreCell chip.
Some samples should be out by the end of the months and you should be able to buy it in a retail or etail store at the eginning of December just in time for the Yule shopping madness.
MSI claims that the board will be very overclockable but this is yet to be seen. µ