NVIDIA is working on a nForce 790i chipset, OCW reports. The release date of this chipset isn't know but it will be somewhere in 2008 after the launch of the nForce 750 and 780.
The NForce 790i chipset comprises of only a north and south bridge (750i,780i uses 3 chipsets, north+south+NF200 switch).
NForce 790i is meant to support quad core intel processors and DDR3 memory. It will officially support 1600FSB future CPUs. It will support 3 PCIe x16 slots with 2 slots in PCIe 2.0 and the other in PCIe 1.0 (wondering why).