We've already told you that the TDP of first Fusion to show is a 25W part, and the Southbridge will need an additional 6W. Hudson D1 supports PCIe 4X and well as PCIe 1X interface. The USB support is kind of an awkward as it supports 14 USB 2.0 ports and two USB 1.1 slots.
The good news is that Hudson D1, most likely named after New York's famous river has RAID 5 support as well as six SATA 3GB/s ports. There is some indication that there will be a version without RAID as well and the document we've seen implies that there won't be an integrated Gbit LAN on this Southbridge.
Since this is a mainstream Southbridge you should not be surprised and you can only hope that this dual-core Fusion can support PCIe 8X or 16X in order to enable external graphics on Brazos platform. I guess that integrated graphics will have to do, as this is the whole point of AMD's Fusion chip to begin with.