Even more jumpers. Traditionally, SLI has been switched by the use of a little switch card. DFI uses a big block of jumpers here. In the package of the motherboard you will find a jumper pulling tool which helps getting these big blocks out.
The placement of the PCI-E x1 slots is very convenient, it allows use of one slot, even when the system is running with two SLI cards.
The northbridge cooler is small and not located very well. If you install two video cards, there is not much airflow left, since the VGA cards are right above it. While the cooler is not the quietest, its fan noise is not annoying at all.
ITE's 8712F is monitoring temperature, fan speed and voltages.
The Vitesse CIS8201 LAN Controller is used to implement Gigabit Ethernet via NVIDIA's nForce4 chipset. A Marvell 88E8001 Gigabit Ethernet controller is used for the second Gigabit Ethernet port.
Firewire (IEEE1394) comes from VIA. Their VT6307 chip is used.
For audio, DFI has thought of another interesting solution. All audio related circuitry is on a little PCB, which is plugged into the motherboard. Realtek's ALC850 8-channel sound chip is used there. If you don't need sound - don't plug the card in. According to DFI, the reason for an extra card is "to isolate the audio analog ground from digital ground eliminating noise signal and producing crystal sound output". Well, they probably mean crystal clear. I don't see a reason why this could not be done via regular circuitry, but still, it's a nice addon.